Give Lookup a '.findWhere()'
Add a isConnected() method to StateView and EndpointView
Only allow dialogue states without connections to be moved
Merge branch 'develop-frontend' into feature/issue-441-dialogue-states-should-only-be-moveable-if-they-have-no-connections-attached
Remove notification for when users try move connected dialogue states
Added a .simulate('mousedown') when testing whether connected states aren't allowed to be sorted
Merge branch 'develop-frontend' into feature/issue-441-dialogue-states-should-only-be-moveable-if-they-have-no-connections-attached