all versions updates were minor and no visible downgrades

This reverts commit f3161468.

rename djang-babel to enmarker
upgrade the reqs

updated the constraints order

* Updating Python Requirements

* Pin django-pipeline and lxml

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

These were pinned because they drop support for Django<2.2 (or were
planning on it, in the latter case.)

No related changes in computed requirements.

Upgrade uses renamed enterprise catalog endpoints

Also pinned httpretty < 1.0 because that upgrade broke many tests.

The last time we tried this upgrade we encountered timeouts on the quality job, which it now appears were due to the worker running pylint common running out of memory and killing the Jenkins process. Switching to a different worker type with double the RAM (8 GB vs. 4 GB) seems to have fixed this; about 5.5 GB was used. Upstream is aware of the high memory usage on large projects, it's apparently due primarily to a cache of parsed modules: https://github.com/PyCQA/pylint/issues/1495 .

Even after disabling some of the new checks that have been added, the new version of pylint found about twice as much to complain about. Just bumping the threshold for now to unblock the Django upgrade, we can try automated utilities like pyupgrade to fix some of these later.

Remove duplicate constraints in requirements/constraints.txt uncovered by the recent change in pip-compile output format. I sorted the pinned dependencies by name to try and make it more obvious if this happens again. I also upgraded to pip-tools 4.5.1, which removes the line numbers from the enhanced pip-compile output added in 4.5.0, which should reduce future diff churn and merge conflicts but means that there's a large diff this one last time.

Also unpin edx-search again after the previous change to do that was apparently broken by a merge conflict.

- Reimplement `djcelery.common.respect_language` utility function so we
  can drop the dependency.
- Loosen `celery` pinning to a range, which brings in a fix for a
  possible crash bug

Also, pin `path` to 13.1.0 for now in order to continue supporting py35.

* Updating Python Requirements

* Constrain edx-when version for now

* Bumping edx-enterprise version

* Running make upgrade to bump edx-enterprise

* contraining a package

* fix

* adding yet another constraint

* Constraining edx-rest-api-client

* Decreased pin on edx-rest-api-client from <3.0.0 to <2.0.0

Unpin several more outdated dependencies whose changelogs don't contain any significant backwards incompatible changes. Also add "moto" to the list of packages to uninstall from existing environments, since it requires a jsondiff version that clashes with the one we now use (triggering a harmless but distracting warning on dependency updates).

We can potentially stop using path.py/path altogether by switching to pathlib in the Python 3 standard library, but that merits a separate PR of its own.

Also, note that I'm not actually unpinning freezegun; different PRs restricted it in both constraints.txt and test.in, I'm just removing the latter redundant constraint.

Removing the moto.