Merge commit '82e477b184b5666fff7fb55933dce22ca2925db8' into glitch-soc/merge-upstream

Conflicts:
- `db/migrate/20180831171112_create_bookmarks.rb`:
  Upstream ran a lint fix on this file, but this file is different in
  glitch-soc because the feature was added much earlier.
  Ran the lint fix on our own version of the file.

config/initializers/content_security_policy.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Define an application-wide content security policy
 # For further information see the following documentation
 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy