* Remove useless wrapper code (IDPException, Entity\User, Grant\*, httpBuildQuery)
* Remove useless getUserUid(), getUserEmail(), getUserScreenName() methods that throw away remote-fetched data
* Do not depend on Guzzle, use just cURL instead
* Shorten namespace name and remove sub-namespaces
* Do not use Mockery in tests, use custom cURL mock instead (TESTS STILL PASS)
