get rid of cache sweepers
add indices on all RefererTracking fields
remove empty controller action
update readme
remove active_record dependency
rails 4
add rails 3/4 gemfiles to travis
remove gemfiles/*.lock
add coveralls, fancy badges
rewrite Tracker#rt_track_referer
restructure ReTrack::Tracker, do not validate rt in Trackable
ruby 1.9 compatibility
rails-4: update mongoid to 4.0.0.alpha1
prefer single quoted strings
version bump
Merge pull request #3 from gewo/drop_cache_sweepers

Rails 4