A migration is causing problems, reverting until it's resolved

Unskip a test that the new version fixes

This prevents seeing due dates for enrollments originally created
too close to the course end to allow for finishing the course in time.

AA-195

ENT-3073

This will allow for more controlled releases of enterprise code in edx-platform.

This change will prevent Library Content from being marked as
complete on view and the corresponding version bump to
edx-completion contains code that will start looking at the
children of the library content for completeness.

...and pin django-ipware for the moment

Removing ddt constraint.

The new releases end up importing code in Studio that relies on an LMS-only setting. Pinning until resolved.

Also pinning edx-completion until the test failures in #24365 get resolved.

They seem to have removed 1.8.14 from pypi.

enum34 is causing problems in python3.8 tests of edx-platform because it has incompatibility with recent versions of python, the error the error happens while importing the re module in these python versions.

This library is a backport of enum of python3.4 made for python<3.4, therefore is not needed anymore.

edx-val was updated to remove that dependency: https://github.com/edx/edx-val/pull/245

Remove mongoengine constraint to upgrade package avoiding raising StopIteration since after python 3.7 is produces an error.

Upgrade to 1.0.0 caused issues which are described and being
investigated in https://github.com/django-ses/django-ses/issues/186.