Clean up tracker map periodically

[rcanderson23]

The tracker map stores up to 4 connections after which the IP is blocked the IP is removed from the tracker map. Connections are only cleaned up upon the insertion of a new connection. These connections only matter across a sliding window of time so there is a possibility of storing three connection events per IP and them never being cleaned up but the window has passed for all the connections.

Update Tracker to periodically clean up the maps of old connections.