Use new preferences setter in AuthorizeNetCIM class
Correct arguments for BraintreeGateway's capture method
Remove BraintreeGateway#preferences

This is no longer needed with the recent preferences changes on Spree's master branch
Use new preferences references within braintree_gateway_spec to appease the testing gods
Remove ancient pending block for authorize+capture payment flow within BraintreeGateway's tests
Ignored options on BraintreeGateway#capture should be optional
Use correct options when calling capture in BraintreeGateway#capture tests
Braintree Credit test won't work because Braintree doesn't provide a way (yet) to settle the transactions
Set auto_capture to true before void tests + call right void_transaction method
Call correct credit! method in BraintreeGateway's spec's credit_using_spree_interface method