* fn: prometheus collector concurrent map access
*) Added mutex to guard against concurrent access to maps
* fn: prometheus collector method receivers should be ptr
* fn: prometheus collector concurrent map access
*) Moved the mutex into getHistogramVec()
* Docker stats to Prometheus
* Fix compilation error in docker_test
* Refactor docker driver Run function to wait for the container to have stopped before stopping the colleciton of statistics
* Fix go fmt errors
* Updates to sending docker stats to Prometheus
* remove new test TestWritResultImpl because we changes to support multiple waiters have been removed
* Update docker.Run to use channels not contextrs to shut down stats collector
