Gemfile.lock doch im Repo…

… damit Alle Worker gleiches Gem-Set bekommen.
[worker] made EC2 optional
[mailer] log message if no from address is specified
[worker] use up-to-date politics

So that cleanup does not need to call super
[git][bugfix] #remote_changed? recognizes new branches
[models] introduced ClusterState
[worker] ClusterState#minion_count is being updated by the leader