Travis: enable containerized builds
Gemfile: Lock Sequel and Grape versions
Upgrade to Roar 1.0.0, fix breakage
Bundle update, along with Raven's breaking change
Update Grape spec for event_type query param
Expose event_type in event's JSON
Filter events by type in interactor
Allow filtering through event_type in events endpoint
Add missing events types
Extend event_type integration test