Add detection and listener counts in json api

[skanderm]

Is your feature request related to a problem? Please describe.
Orcanode monitor would like detections and listener counts displayed for each feed

Describe the solution you'd like
Once #704 is implemented, we can share the last live listener count recorded and the recent detection count.

[dthaler]

In terms of what would be ideal (unsure whether implementable)...
Accept a parameter that indicates when the client wants the # of listeners since (e.g., 1 week, 1 month).
Then include the # of "play" (or whatever it's called) events logged, and the # of detections logged, since that time.

[skanderm]

In terms of what would be ideal (unsure whether implementable)... Accept a parameter that indicates when the client wants the # of listeners since (e.g., 1 week, 1 month). Then include the # of "play" (or whatever it's called) events logged, and the # of detections logged, since that time.

That mostly sounds good to me, though we're only logging play clicks in Google Analytics. Do we want to try tracking those on the server too? Personally, I think we should just get those from GA.

[dthaler]

In terms of what would be ideal (unsure whether implementable)... Accept a parameter that indicates when the client wants the # of listeners since (e.g., 1 week, 1 month). Then include the # of "play" (or whatever it's called) events logged, and the # of detections logged, since that time.

That mostly sounds good to me, though we're only logging play clicks in Google Analytics. Do we want to try tracking those on the server too? Personally, I think we should just get those from GA.

Does GA expose an API for querying such stats?

[skanderm]

Might be worth asking @adrmac about where the data comes from for those charts he shares every week