SuspensionUpdater only forces a reauth downstream

so renaming to ReauthEnforcer to convey the intent specifically.
Make ReauthEnforcer a Sidekiq worker

also,
  * moving tests to where they deserve to be
  * removing suspension propogation update results view
    as this is now done in background and admins might
    not be using it
Signon logout triggers logout on downstream apps
Merge pull request #180 from alphagov/remote-sign-out

Remote sign out