My first pass at populate the submission API.
One more tweak to get some extra coverage.
Updating my API changes per review comments
More updates based on feedback.
First pass attempt at generation exceptions
Erroneous use of _asdict()
Updates to the API.
Problems with rebase..
Adding log messages when exceptions occur.
Added tests for exception handling using the mock library.
Adding some quick doc to the functions
Some additional doc for the errors
Updated models, apis, and tests.
More documentation, repr, corner case testing, and proper validation
Few extra minor changes to the api.
Fixing test dependencies. Adding more doc and examples.
Quick changes to clean up api using serializer save
Merge branch 'master' into sanchez/first_pass_at_basic_api

Conflicts:
	requirements/test.txt
Merge pull request #14 from edx/sanchez/first_pass_at_basic_api

My first pass at populating the submission API.