Add rspec
Configure guard
Create User factory
Merge branch 'development' into test
Configure DatabaseCleaner to be used in test env, but don't clean Doorkeeper applications
Modify user factory to use reuse password for password confirmation
Add seed to create default doorkeeper applications for testing
Add custom RSpec matcher for Doorkeeper
Add generic matcher for API testing
Add doorkeeper spec
Include helper method for authentication
Merge branch 'test' into development