* Change references to tootsuite/mastodon to mastodon/mastodon

* Remove obsolete test fixture

* Replace occurrences of tootsuite/mastodon with mastodon/mastodon in CHANGELOG

And a few other places

heroku-buildpack-ruby started to install Node 12 by default.
This makes it possible to run Mastodon without heroku-buildpack-nodejs.

Use https://github.com/heroku/heroku-buildpack-apt to
install protobuf-compiler and libprotobuf-dev which are needed by cid3

* Allow SMTP auth method customization

* Add SMTP openssl_verify_mode option support

Allows one use self-signed certs with their SMTP server.

* Add SMTP enable_starttls_auto option support

Allows the user to set the address mastodon emails are maraked as being sent from