Created FakeMuonlabII for testing applications
Return fake data at 2 Hz
Testing correct start / shutdown code with exceptions

The multiprocess lifetime measurement with HTTP API now has the following
properties:

    - ctrl-c (interrupt signal) is ignored in the muonlab process
    - ctrl-c is catched by the main thread and a shutdown is initiated
    - exceptions in the muonlab process will terminate it prematurely and
      the main thread will initiate a shutdown of the flask server
    - a shutdown of the flask server (which I can't trigger since flask
      seems to handle exceptions very well) should initiate a shutdown as
      well.
    - a shutdown terminates the flask process, but sends the muonlab code
      a shutdown signal and then joins the process.

This seems to work really well.
Minor improvements to muonlab_with_http_api

Replaced print statements with logging, removed timeouts, disabled STOP
API call, return json.
App falling back to fake hardware if device not found
API: get all data or from a starting index
Use start and stop indexes in query strings