Deprecate test mode on management commands

[gordonje]

This option was added to several of our custom management commands back when we were developing the initial etl process. Reaching back in my memory...I think the idea was to allow working with a smaller sample, rather than the actual full raw data set, without overwriting the real data.

Has it outlive it's utility? Seems like we could instead, in our unit tests, override our custom Django project setting specifying the directory where the CAL-ACCESS data should be written locally and strip out the conditional logic around test mode.

Sort of assuming that users who install the app in their Django projects don't want to run any of the commands in test mode.