Create Unified Library of Env Settings

[722C]

We should create a unified list of Env Settings so that @dostler has fewer issues with new deployments.

This would also allow developers who are going through the process of adding in new functionality to ideally reuse an existing one if it matches well enough or prevent the creation of new Env settings (or variations thereof) than are needed.

[improvshark]

Maybe something a little more like this? https://gist.github.com/improvshark/cc3483658f9a72c411ef3e9aff6368d5

[722C]

To some degree, yes. I would add ones that don't overlap with ones already to this: https://github.com/lightningkite/cookiecutter-django/wiki/Library-of-Env-Settings