This module implements a simple GenServer which will trigger a GC flush of at a specific frequency.

It subscribes to a series and uses insert events to calculate a simple backoff to reduce the amount of work done by the GC and Series processies.

Future improvements: - take both the series' resolution and range into account when calculating call frequency. - make the backoff smarter, ie if there's been no inserts for more than the series' range then you may as well hibernate until there is an insert and then set a timer for range.