Investigate using Gunicorn's preload option by default

[JayH5]

http://docs.gunicorn.org/en/latest/settings.html#preload-app
Load application code before the worker processes are forked. By preloading an application you can save some RAM resources as well as speed up server boot times. Although, if you defer application loading to each worker process, you can reload your application code easily by restarting workers.

This seems desirable. Reloading workers is not common in a containerized/immutable-deployment environment where one would rather just restart the entire container.

We should investigate if there are any side-effects of enabling this setting by default.