Upgraded rspec to 3.1 and shoulda-matchers to 2.7
Added rspec-its gem
Fixed controllers specs
Fixed models specs
Files changed by rspec update
Moved shared examples to separate file
Fixed policy specs
Updated policy specs helper
Updated authentication spec helper
Merge pull request #36 from coopdevs/feature/upgrade-rspec-and-shoulda-matchers

Upgrade rspec and shoulda matchers and add rspec-its
Switch to ruby 2.1.4
Added Invitation model
Added Invitation serializers
Added Invitation controller and routes
Added Invitation index and create actions
Removed JSON parameters wrapping
Added Invitation policy
WIP
WIP 2
WIP 3