* Add announcements

Fix #11006

* Add reactions to announcements

* Add admin UI for announcements

* Add unit tests

* Fix issues

- Add `with_dismissed` param to announcements API
- Fix end date not being formatted when time range is given
- Fix announcement delete causing reactions to send streaming updates
- Fix announcements container growing too wide and mascot too small
- Fix `all_day` being settable when no time range is given
- Change text "Update" to "Announcement"

* Fix scheduler unpublishing announcements before they are due

* Fix filter params not being passed to announcements filter

* Increased max backup size

* partially reverted schema.rb

* Update annotate to version 2.7.3

* Update aws-sdk-s3 to version 1.9.2

* Update browser to version 2.5.3

* Update capistrano to version 3.10.2

* Update domain_name to version 0.5.20180417

* Update http to version 3.2.0

* Update lograge to version 0.10.0

* Update oj to version 3.5.1

* Update parallel_tests to version 2.21.3

* Update puma to version 3.11.4

* Update rubocop to version 0.55.0

* Update scss_lint to version 0.57.0

* Update simplecov to version 0.16.1

* Update tty-command to version 0.8.0

* Update tty-prompt to version 0.16.0

* Update pkg-config to version 1.3.0

* Update fog-local to version 0.5.0

* Update fog-openstack to version 0.1.25

* Update devise-two-factor to version 3.0.3

* bundle update

* Fix #201: Account archive download

* Export actor and private key in the archive

* Optimize BackupService

- Add conversation to cached associations of status, because
  somehow it was forgotten and is source of N+1 queries
- Explicitly call GC between batches of records being fetched
  (Model class allocations are the worst offender)
- Stream media files into the tar in 1MB chunks
  (Do not allocate media file (up to 8MB) as string into memory)
- Use #bytesize instead of #size to calculate file size for JSON
  (Fix FileOverflow error)
- Segment media into subfolders by status ID because apparently
  GIF-to-MP4 media are all named "media.mp4" for some reason

* Keep uniquely generated filename in Paperclip::GifTranscoder

* Ensure dumped files do not overwrite each other by maintaing directory partitions

* Give tar archives a good name

* Add scheduler to remove week-old backups

* Fix code style issue