Impossible to create app object without running whole application

[olivierdelree]

For testing reasons, I'd like to be able to create my own visiomode.core.Visiomode() object without having to also start the Flask server and run the main application loop.
It'd be nice if there were some flags that could be passed to visiomode.core.Visiomode() so that it could be made to only initialise the Pygame side of things without running the whole application as if we were running experiments.