Previously it would unhide their post but leave them silenced.
This fix also cleans up some of the helper classes to make it easier
to pass extra data to the silencing code (for example, a link to the
post that caused the user to be silenced.)
This patch also refactors the auto_silence specs to avoid using
stubs.
Previously we would raise a 500 error if a moderator tried to agree on a
flag another moderator deferred.
This can happen cause the UX for flags does not live refresh as flags
are handled
This updates tests to use latest rails 5 practice
and updates ALL dependencies that could be updated
Performance testing shows that performance has not regressed
if anything it is marginally faster now.
