* Do not start locust automatically, instead make the locust user
  suitable for interactive manipulation and execution of the codebase.
  This works well for the current iteration of edx-load-tests which
  expects the user to hand-modify settings files.

* For convenience, the locust user gets dropped straight into the
  edx-load-tests codebase and sources a virtualenv with most
  dependencies already installed.

* Add an extra MOTD related to loadtesting

PERF-415