ADD: rspec-rails gem
ADD: relation model with actors validation
FIX: rename actor relations table to actors relations
FIX: move pry to use it on test env
ADD: relation model

I have added the relation model, it:

belongs to a Social Network
HABTM actors,

and to be valid has to have at least 2 actors
ADD: JSON api for relations
ADD: render relations as lines
ADD: line updates when dragging actors
ADD: actor class to actor svg elements
ADD: center circle and text to relations
FIX: extract actor clicking and draggable behavior
ADD: relation cick binding to circle and text
FIX: extract actor click in its own function
FIX: update relation
FIX: update ember-rails gem
FIX: update ember and ember-data versions
Merge branch 'update_ember' into relations
ADD: persisting relation creation

I have successfully persisted many To Many relations with
ember, without having to embed the record into the association

http://stackoverflow.com/questions/15683273/save-foreign-key-to-other-mo
del-with-hasmany-relation/15709988#15709988

was the source of the solution
Merge branch 'persist_many_2_many_relation' into relations
ADD: factory girl rails gem