nebulab/spree-subscriptions — pull request #20 by radar (2014-03-25 05:08:41+00:00)
Title: Use symbols for payment decorator states

By re-defining the state machine like this, the state_machine gem will complain because 'checkout' != :checkout and 'completed' != :completed.

See this thread on the mailing list: https://groups.google.com/forum/#!topic/spree-user/BEbfbrAWOLM