Removed the BucketGauge class as it is not used anymore.
Removed the BucketGauge class as it is not used anymore.

Recently changed the statsd aggregator to use the Gauge instead
of the BucketGauge.  BucketGauge class not used anymore.

Change-Id: I60faad0299a533f3beb383f4f0bf0ceb9bd32c90

sapcc/monasca-agent,sapcc/monasca-agent,sapcc/monasca-agent