Fix broken doctests
Merge pull request #1175 from frewsxcv/patch-2

Fix broken sphinx docs, thanks @frewsxcv
Merge pull request #1140 from SeanHayes/test-enhancements

Test enhancements to make your life easier.
Removed data shared on Field objects, changed code to reuse related resources.
Removed ApiField.value, which is unused and undocumented. It seems to be leftover from when field objects could store values and be serialized.