package in audit
This PR implements reputation store and replace overlay in audit service
to use such store for storing node's audit stats.
In order to keep the changeset smaller, most of the changes in this PR is for copying audit logic in overlay to
reputation package. In a following PR, the duplicating code will be
removed from overlay.
Change-Id: I16c12494a0970f44c422b26cf603c1dc489e5bc1
Define service and DB interface for storing node reputation data
and updating the overlay cache.
Add overlay service and DB method UpdateReputation.
See https://github.com/storj/storj/pull/4144
Change-Id: Iedd8bd3274457d26c595919303d55327c1464b8c
