Docstrings and Unit Tests

- [x] Adapter docstrings
- [x] Serializer docstrings
- [x] Install sinon for stub/mocking
- [x] Adapter unit tests
- [x] Serializer unit tests

/cc @holandes22 @benkonrath
I have the habit of full sentence comments from Python / PEP8. No problem to change to this if you prefer ... and I guess you do because you changed it. :)