This updates the RBGateway test suite to make fewer assumptions about

the API requests and results, which were masking some problems, and as

part of a series of cleanups to prepare for better type safety checks.
All HTTP requests are now checked for all arguments, ensuring we're

passing all the data we expected (and this helped highlight a flaw in

the unit tests where a hosting account URL was not shown).
We now spy on http_request and not methods like http_post, which

will allow for future type safety checks to kick in.
We also now better check the commits and other information we get back,

ensuring that all the expected data has been parsed from the payload.

Unit tests pass.