Ora2

There have been various instances in ora submissions where the learner uploaded the file but it wasn't visible to peers or staff members while grading. The upload information wasn't present in submission, but it was present in the user state. This release is bringing in the data from the user state to show the file upload information to **staff members** to help assess the user's response. The workaround is behind a waffle switch/course override.

* ran make upgrade on repo

* Changed install_requires to requirements/base.in

* Adding .in requirement files to Manifiest.in

* Added Django req to dependencies in tox js environment

Some FileUploadError logs have been updated/added to get proper information for the cases where the file information is missing in the user submission.

Switch to using Pytest instead of nose to run unit tests.

Bump version for prep for PyPI package

Refactor python-side handling of file uploads: https://github.com/edx/edx-ora2/pull/1293