Code review comment for lp:~pitti/platform-api/test-backend

Note that this just provides the initial building blocks. Once that lands, we most probably want to add some more commands to the test data files, such as a command to create a set of standard sensors, or composite events like "turn device by 90 degrees" (either by new commands, or by providing a library of test data files, remains to be discussed).

I'll also create some tests in qtubuntu-sensors which use the QtSensors API, to ensure that the data is correctly passed back and forth through QtSensors/qtubuntu-sensors/platform-api.