Added APIRequestFactory
Added APIClient
Addeded 'APITestClient.credentials()'
Remove unneeded tests.utils, superseeded by APIRequestFactory, APIClient
Refactor SessionAuthentication slightly
Added APIClient.authenticate()
Simplify APIClient implementation
Rename to force_authenticate
First pass at testing docs
Complete testing docs
Remove console style from code blocks
Tweak docs
Merge pull request #962 from tomchristie/test-client

APIClient and APIRequestFactory