LFR Tests: implement better way to force drift and non-drift

[macandleighs]

For these test functions, we use a numpy random seed to get the tests to pass. Ideally, we would have a better way to ensure drift or non-drift as a result of the update statements that we use in the tests to introduce new data to the detector.

[anmol-srivastava-mitre]

Some of the class manipulation drift injection methods being added recently may relate to this, so switching milestones