* bump proctoring version to 2.4.2 (python requirements update)

* bump completion to 3.2.1 (python requirements update)

Co-authored-by: Ben Warzeski <benwarzeski@edX-C02CD0HCLVDM.cable.rcn.com>

updated the constraints order

- Updating Python Requirements
- Fix cache key generation to use class name and module

This was stringifying the class object directly, resulting in cache keys
like `:1:<class 'xblock_django.models.XBlockConfiguration'>.xblock_django.api.deprecated_xblocks`
which then cause breakage when Django 2.2.13 validates the keys.

Co-authored-by: edX requirements bot <testeng+edx-requirements-bot@edx.org>

Remove pystache_custom dependency.
Upgrade requirements.

https://openedx.atlassian.net/browse/BOM-1670

Move sorl-thumbnail dependencie from github.in to base.in since PyPi version is now compatible with DJango 2.2 and python 3.5.

ENT-2577

Remove pandas requirement.
Replace pandas functionality with itertools.group_by.

and make upgrade.

We will now show the problem icon if the LTI problem
is scored and 'other' if it is not.

* Enterprise: Bump to v3.2.17

* ran make upgrade to upgrade all dependencies

Co-authored-by: Adam Stankiewicz <agstanki@gmail.com>

* Updating Python Requirements

* Pin django-pipeline and lxml

Co-authored-by: Jeremy Bowman <jbowman@edx.org>

This reverts commit 1d7ff32a.

Cleaned up a few more things about the testing configuration now that we've deployed Django 2.2 to production:

* Go back to a single version of django-oauth-toolkit, tox doesn't need to vary it anymore
* Go back to PyPI release of django-method-override
* Remove no longer needed dependency on python-oauth2 (we already removed the package it was used by)
* Update prepare_xdist_nodes.sh with new Django requirements file options

This reverts commit 27480a25.

* Updating Python Requirements

* Constrain django-cookies-samesite until dep bug fixed

* Fix PEP 8 problems revealed by pycodestyle upgrade

Co-authored-by: Tim McCormack <tmccormack@edx.org>
Co-authored-by: Jeremy Bowman <jbowman@edx.org>