* Change basic stats to use opentracing rather than Prometheus API directly
* Just ran gofmt
* Extract opentracing access for metrics to common/metrics.go
* Replace quotes strings with constants where possible
* 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
