added Guest Checkout, check for signature at notification and redirect, send signature, timestamp, and order id instead of secret in helper, update parameter names
Guest Checkout now always enabled

Letting merchant choose whether or not to enable GC by setting
:credential4 to "true" just didn't seem correct, so I just force GC to
be enabled always
standardize amount param
actually, no need
Add credit to dwolla integration files
remove header comments
centralize the signature verification method
rename credentials params
update tests to reflect the change in credential parameter names
remote comment headers, fix credential var names, fix sig verify fn
Auth.net: Don't directly check the source class.
FirstdataE4: Don't directly check the class against CreditCard.
Merge pull request #712 from Shopify/creditcard-check-fixes

Changes in preparation for v1.33.0 release
Bump for release v1.33.0
Use just name instead of firstname & lastname.
Paypal Express gateway: Add unstore support

The #store method creates a billing agreement. Now the #unstore method
cancels a billing agreement.

Closes #716.
Stripe: Send application_fee with capture requests.
Merge pull request #714 from Shopify/payflow-fix

Use just name instead of firstname & lastname.
Merge pull request #718 from Shopify/stripe-application-fee

Stripe: Send application_fee with capture requests.
for bluepay gateway name1 & name2 should be populated from the payment method