Propose best practices for Django management command logging

[jeancochrane]

Documentation request

From https://github.com/datamade/devops/issues/110#issuecomment-553624525:

What is our standard for Django management command logging? We seem to use a mix of styles and frameworks, both within and between projects.

Some points in favor of using the built-in Django management command logging:

• Pretty simple to use
• Unbuffered by default
• Exposes verbosity flags

Points in favor of using Python's logging module:

• Framework-agnostic, so knowledge of it generalizes to non-Django Python projects
• Granular control over log levels; doesn't uniformly print to stdout
• Easier to capture during testing

If we decide we want to use something different than the built-in logging, this could make a good mini Django app. In fact, such an app may already exist.