Adds a basic Spree::Subscription factory
Adds specs for Spree::Subscriptions#cancelled?
Adds scaffolding to add subscriptions to the admin
(cherry picked from commit 705b08b2d94d3f47228874cb936fdacf8e409994)
Adds specs for Spree::Subscription#cancel!
Assimilates Subscriptions backoffice developed within DynamoMTL/blue-bottle-coffee
 Maps subscription-cancellation admin route
Don't use bang syntax for Subscription-cancellation method
Merge pull request #2 from DynamoMTL/features/subscriptions-backoffice

Integrates a Spree admin area for subscriptions