Clean up requirements, remove django_extensions

Also, removes dependency on django-extensions

Log the submission data when validator says invalid.

Fix exception printing and log upon error.

Version bump to 2.0.4

Print DRF errors upon invalid serialization.

Fix .travis.yml file.

EDUCATOR-786 | Support Django 1.11

EDUCATOR-786 | Support Django 1.11; Upgrade django_nose; Mock out read_replica for testing; bump tox version.

Upgrade DRF requirement to v3.6.x

return serialized scores from get_scores()

Version 1.2.0

Allow reset signal to be ignored

Stop pinning pytz

Version Bump

Unpin and inherit django version

This commit loosens the allowable version of django to anything
<1.9a0. Each of 1.8, 1.9, and 1.10 can now be tested using tox,
which will make the eventual upgrades much easier.

send created time

This data is needed for robust grades work, and is easy enough
to include in the providing signals. I've also added the freezegun
library to test-requirements.txt to test this functionality.

Serialize annotation information with scores