Allow keyboard 'return' key to dismiss keyboard on BTUICardPostalCodeField, disable autocorrection for postal code
Refine return key type and auto-capitalization
Fix backspace form field retreat bug for iOS 8

* Add UI tests
* Clean up UI demo app Storyboards
* Add accessibility labels to form fields to aid KIF testing
Merge pull request #70 from braintree/bugfix/ios8textfield

BTUICardForm text field enhancements