* Add request pool to improve delivery performance

Fix #7909

* Ensure connection is closed when exception interrupts execution

* Remove Timeout#timeout from socket connection

* Fix infinite retrial loop on HTTP::ConnectionError

* Close sockets on failure, reduce idle time to 90 seconds

* Add MAX_REQUEST_POOL_SIZE option to limit concurrent connections to the same server

* Use a shared pool size, 512 by default, to stay below open file limit

* Add some tests

* Add more tests

* Reduce MAX_IDLE_TIME from 90 to 30 seconds, reap every 30 seconds

* Use a shared pool that returns preferred connection but re-purposes other ones when needed

* Fix wrong connection being returned on subsequent calls within the same thread

* Reduce mutex calls on flushes from 2 to 1 and add test for reaping

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.71.0 to 0.72.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.71.0...v0.72.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.24.0 to 3.25.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.24.0...3.25.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.42.0 to 1.43.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.42.0...v1.43.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.22.0 to 3.24.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.22.0...3.24.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps ox from 2.10.1 to 2.11.0.

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [webmock](https://github.com/bblimke/webmock) from 3.5.1 to 3.6.0.
- [Release notes](https://github.com/bblimke/webmock/releases)
- [Changelog](https://github.com/bblimke/webmock/blob/master/CHANGELOG.md)
- [Commits](https://github.com/bblimke/webmock/compare/v3.5.1...v3.6.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.41.0 to 1.42.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.41.0...v1.42.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

* Revert "Revert #10957 (rubocop-rails) which is incompatible with CodeClimate (#10965)"

This reverts commit 121d19d7fa.

* Disable Rails/HelperInstanceVariable

Bumps [fuubar](https://github.com/thekompanee/fuubar) from 2.3.2 to 2.4.0.
- [Release notes](https://github.com/thekompanee/fuubar/releases)
- [Changelog](https://github.com/thekompanee/fuubar/blob/master/CHANGELOG.md)
- [Commits](https://github.com/thekompanee/fuubar/compare/releases/v2.3.2...releases/v2.4.0)

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.70.0 to 0.71.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.70.0...v0.71.0)

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.40.0 to 1.41.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.40.0...v1.41.0)

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.21.0 to 3.22.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.21.0...3.22.0)

Bumps [strong_migrations](https://github.com/ankane/strong_migrations) from 0.3.1 to 0.4.0.
- [Release notes](https://github.com/ankane/strong_migrations/releases)
- [Changelog](https://github.com/ankane/strong_migrations/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ankane/strong_migrations/compare/v0.3.1...v0.4.0)

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.20.2 to 3.21.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.20.2...3.21.0)

Bumps [tty-prompt](https://github.com/piotrmurach/tty-prompt) from 0.18.1 to 0.19.0.
- [Release notes](https://github.com/piotrmurach/tty-prompt/releases)
- [Changelog](https://github.com/piotrmurach/tty-prompt/blob/master/CHANGELOG.md)
- [Commits](https://github.com/piotrmurach/tty-prompt/compare/v0.18.1...v0.19.0)

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.39.0 to 1.40.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.39.0...v1.40.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.69.0 to 0.70.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.69.0...v0.70.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [httplog](https://github.com/trusche/httplog) from 1.2.2 to 1.3.0.
- [Release notes](https://github.com/trusche/httplog/releases)
- [Changelog](https://github.com/trusche/httplog/blob/master/CHANGELOG.md)
- [Commits](https://github.com/trusche/httplog/commits/v1.3.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.38.0 to 1.39.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.38.0...v1.39.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.19.1 to 3.20.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.19.1...3.20.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.36.1 to 1.38.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.36.1...v1.38.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.18.0 to 3.19.1.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.18.0...3.19.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.68.1 to 0.69.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.68.1...v0.69.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [parallel_tests](https://github.com/grosser/parallel_tests) from 2.28.0 to 2.29.0.
- [Release notes](https://github.com/grosser/parallel_tests/releases)
- [Commits](https://github.com/grosser/parallel_tests/compare/v2.28.0...v2.29.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Bump rack-attack from 5.4.2 to 6.0.0

Bumps [rack-attack](https://github.com/kickstarter/rack-attack) from 5.4.2 to 6.0.0.
- [Release notes](https://github.com/kickstarter/rack-attack/releases)
- [Changelog](https://github.com/kickstarter/rack-attack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kickstarter/rack-attack/compare/v5.4.2...v6.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* fix payload[:request]

Bumps [scss_lint](https://github.com/sds/scss-lint) from 0.57.1 to 0.58.0.
- [Release notes](https://github.com/sds/scss-lint/releases)
- [Changelog](https://github.com/sds/scss-lint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sds/scss-lint/compare/v0.57.1...v0.58.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [bullet](https://github.com/flyerhzm/bullet) from 5.9.0 to 6.0.0.
- [Release notes](https://github.com/flyerhzm/bullet/releases)
- [Changelog](https://github.com/flyerhzm/bullet/blob/master/CHANGELOG.md)
- [Commits](https://github.com/flyerhzm/bullet/compare/5.9.0...6.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.67.2 to 0.68.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.67.2...v0.68.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Add blurhash

* Use fallback color for spoiler when blurhash missing

* Federate the blurhash and accept it as long as it's at most 5x5

* Display unknown media attachments as blurhash placeholders

* Improve style of embed actions and spoiler button

* Change blurhash resolution from 3x3 to 4x4

* Improve dependency definitions

* Fix code style issues

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.17.0 to 3.18.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.17.0...3.18.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.16.2 to 3.17.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.16.2...3.17.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [doorkeeper](https://github.com/doorkeeper-gem/doorkeeper) from 5.0.2 to 5.1.0.
- [Release notes](https://github.com/doorkeeper-gem/doorkeeper/releases)
- [Changelog](https://github.com/doorkeeper-gem/doorkeeper/blob/master/NEWS.md)
- [Commits](https://github.com/doorkeeper-gem/doorkeeper/compare/v5.0.2...v5.1.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [cld3](https://github.com/akihikodaki/cld3-ruby) from 3.2.3 to 3.2.4.
- [Release notes](https://github.com/akihikodaki/cld3-ruby/releases)
- [Commits](https://github.com/akihikodaki/cld3-ruby/compare/v3.2.3...v3.2.4)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [lograge](https://github.com/roidrage/lograge) from 0.10.0 to 0.11.0.
- [Release notes](https://github.com/roidrage/lograge/releases)
- [Changelog](https://github.com/roidrage/lograge/blob/master/CHANGELOG.md)
- [Commits](https://github.com/roidrage/lograge/compare/v0.10.0...v0.11.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.66.0 to 0.67.1.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.66.0...v0.67.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.15.0 to 3.16.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.15.0...3.16.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.35.0 to 1.36.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.35.0...v1.36.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rails](https://github.com/rails/rails) from 5.2.2.1 to 5.2.3.
- [Release notes](https://github.com/rails/rails/releases)
- [Commits](https://github.com/rails/rails/compare/v5.2.2.1...v5.2.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [devise](https://github.com/plataformatec/devise) from 4.5.0 to 4.6.2. **This update includes security fixes.**
- [Release notes](https://github.com/plataformatec/devise/releases)
- [Changelog](https://github.com/plataformatec/devise/blob/master/CHANGELOG.md)
- [Commits](https://github.com/plataformatec/devise/compare/v4.5.0...v4.6.2)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [tzinfo-data](https://github.com/tzinfo/tzinfo-data) from 1.2018.9 to 1.2019.1.
- [Release notes](https://github.com/tzinfo/tzinfo-data/releases)
- [Commits](https://github.com/tzinfo/tzinfo-data/compare/v1.2018.9...v1.2019.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.34.0 to 1.35.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.34.0...v1.35.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.33.0 to 1.34.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.33.0...v1.34.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.14.0 to 3.15.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](https://github.com/teamcapybara/capybara/compare/3.14.0...3.15.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [aws-sdk-s3](https://github.com/aws/aws-sdk-ruby) from 1.32.0 to 1.33.0.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/compare/v1.32.0...v1.33.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.65.0 to 0.66.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.65.0...v0.66.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>