Update BackboneJS to 1.1.1 and grab Marionette v1.1.1 (not yet released)

This fixes a bug with overriding the template in our related posts
view.. it may not be a permanent fix though depending on the final
Marionette v1.1.1
Update Marionette to v1.2.0
Merge pull request #113 from ushahidi/backbone-upgrade-1.1.1

Update BackboneJS to 1.1.1 and grab Marionette v1.2.0