Bundle update webpay
Initialize RecursionSale model
Add specs of recursion
Implement items#buy_recursively
Fix sales_controller comment
Add recursion's view and controller
Add :data key for link_to's confirm
Add webpay_recursion_id to sale table
Add spec of webhook_controller
Implement webhook#index
Update README
Fix recursion_fabricator
Check response each webhook_controller_spec examples
Fix view mistakes
Unify in-site translation of recursion to 定期購入

Because it is different notion from webpay's recursion.
Upgrade Webhook document with ngrok
Add link for login when guest user try to buy recursively
Merge pull request #6 from webpay/implement_recursion

Implementation of recurring billing