Upgrade to Django 2

[willgearty]

TODO:

• upgrade to Django 2.0.13 (https://docs.djangoproject.com/en/5.1/releases/2.0/)
• upgrade to Django 2.1.15 (https://docs.djangoproject.com/en/5.1/releases/2.1/)
• upgrade to Django 2.2.28 (https://docs.djangoproject.com/en/5.1/releases/2.2/)
• address deprecated features of Django 2.2.28 (https://docs.djangoproject.com/en/2.2/internals/deprecation/)
• upgrade dependencies as needed
  • cachePanel for django-debug-toolbar is broken (presumably some interaction with django-argcache?) so I've disabled it for now (note, if you enable this the page takes a LOOOOOONG time to load)
  • django-localflavor needs to be updated to 3.1, but they removed PhoneNumberField in favor of https://pypi.org/project/django-phonenumber-field/6.3.0/
  • upgrading django-reversion to v. 5.0.2 might require some changes: https://django-reversion.readthedocs.io/en/latest/changelog.html
  • may need a manual install of watchman (ideally only on dev servers): https://facebook.github.io/watchman/docs/install#prebuilt-binaries-2
  • may want to add directories for watchman to ignore: https://facebook.github.io/watchman/docs/config.html#ignore_dirs
• fab manage:makemigrations

Notes for later:

• I updated django-argcache, but in order to get the new version to install properly, I first had to fully uninstall it 🤷 . Same with django-admin-tools.
  • I had forgotten to bump the version number
• django-reversion docs say that you need to migrate the package to upgrade to >= 3.0.2 from < 3.0.1:

  pip install django-reversion==3.0.1
  python manage.py migrate reversion
  pip install --upgrade django-reversion
  python manage.py migrate reversion
  

  • I followed these instructions, but it said there were no migrations to apply, so I think we can ignore it? (otherwise, this would probably go in the Makefile?)
• Despite putting a bunch of time into trying to get watchman to work, it looks like the current available versions of pywatchman and watchman just aren't compatible (given we are on Django 2.2 and Python 3.7)
  • When we upgrade to Python 3.8, we should be able to upgrade pywatchman, and I think it'll "just work"
  • For now, runserver uses the backup StatReloader which polls for changes every ~second or so

Fixes #3777

[willgearty]

OK @kkbrum, I think this is ready for testing!

[willgearty]

Issues encountered by @kkbrum:

1. Permission denied for packages_dev_manual_install.sh. Watchdog doesn't really work anyways, so I'm fine just removing this functionality for now and punting it to whenever we upgrade to python 3.8 (see more details in the OP).
2. Error trying to apply migrations for reversion. I thought this might be an issue but was hoping it would just not show up. Looks like we'll need to incorporate something like this in the Makefile for the next release:

...
[update_deps.sh]
pip install django-reversion==3.0.1
python esp/manage.py migrate reversion
pip install django-reversion==5.0.2
python esp/manage.py migrate reversion
[migrate]
...

[kkbrum]

Looks great! I testing making accounts, making a program with all the accoutrements and making another program to test importing as well. I noticed one bug: #3963, but I'm not sure that it's related to django in any way. Even if it is, I think this can be merged and that can be addressed separately.