WIP: Controller for low demand times

[mschnepf]

This PR addresses issue #83. This controller should test the demand for resources in time intervals. Between these tests, demand should be zero to reduce the number of unnecessary resources.

[maxfischer2781]

Hi @mschnepf, how is this coming along? Do you need any input on it?

[mschnepf]

Thanks for questioning.

I think the current code does basically its job (set demand to zero for a while). I'm not sure about the implementation, especially how to manage the time during the demand=0 period. Maybe it is better to use a await trio.sleep(self.test_intermission). However, in that implementation, there will be no logging output during the demand=0 period. With the current implementation, every self.interval seconds, a logging output is produced. Are there comments about the implementation of the demand=0 period?

Furthermore, unit-tests are on my todo-list :-)

[maxfischer2781]

I think it's fine not to log anything while the controller is waiting. After all, it's not actually doing anything then.