Adding support to recurring subscription through Authorize.net
Merge remote-tracking branch 'origin/master' into recurring_subscription
Merge remote-tracking branch 'origin/master' into recurring_subscription

Conflicts:
	app/models/spree/subscription.rb
recurring payment when a order has a recurring product
Fixing test
Merge remote-tracking branch 'origin/master' into recurring_subscription
Merge branch 'master' into recurring_subscription

* master:
  Prefer single quoted strings when there is not interpolation
  Apply Hounci tip
  Create RenewMailer to send reminder if subscription is about to end
  Create RenewController#edit * Add spree product to current cart to renew subscription
  Fix failing test * Create a product before create a subscription factory
  Fix Gemfile
  Update subscription if you bye the same one twice
  Improve Order#subscription_products method
  Add spree assets to the extension

Conflicts:
	app/models/spree/order_decorator.rb
	config/routes.rb
Add Product@recurring scope
Fix several bugs
Add Subscription#order and Subsciption#payment relation
* Add cancel recurring to payment
Fix Houndci tips
Merge branch 'master' into recurring_subscription

* master:
  Update ruby version in .travis.yml
  Change in README to improve understandability.
Fix bug
Merge pull request #5 from stevenbarragan/recurring_subscription

Recurring subscription