Remove dependency on teeth-rest.

This commit:
- Removes all references to teeth-rest.
- Brings in encoding.py and errors.py from teeth-rest.
- Removes the "view" thing from the encoding module.
- Adds structlog as a dep. This was missing and overlooked
  because teeth-rest was installing it in the environment.
Merge remote-tracking branch 'origin/master' into JoshNang/testr

Conflicts:
	requirements.txt