The cache store is explicitly used by some specs, but they were not
isolated and therefore not reliable. This fixes the issue by clearing
the cache after each specs.
The old implementation sets default From address in mailers. It sets
the address from SMTP_FROM_ADDRESS, or notifications@localhost. The
behavior is occasionally undesired results.
In production environment, notifications@localhost is likely to be
incorrect.
In testing environment, the email address should not be varied by a
environment variable.
After appling this change,
In production environment, it will throw an exception when launching
Mastodon.
In testing environment, the address will be fixed with
notifications@localhost.
* Update rails to version 5.1.1
* Run `rails app:update`
* Remove the override of polymorphic activity relationship
* Silence warning about otp_secret attribute being unknown to rails
* We will only introduce form_with where we want to use remote data