Use href in place of uris following Balanced API v1.1
Migrate fixtures and implementation of events to API 1.1
Create debit.canceled event fixture
Use href to perform refunds
Remove references to balanced_marketplace_id

Is not used to created hrefs of resources.
Merge pull request #29 from neighborly/im-balanced-1.1

Use href in place of uris following Balanced API v1.1