Fix a potential resource leak by letting MeterMetric instances get GC'd.
Fix a potential resource leak by letting MeterMetric instances get GC'd.

ind9/metrics,gorzell/metrics,signalfx/metrics,randomstatistic/metrics,timezra/metrics,scullxbones/metrics-scala,dropwizard/metrics,gorzell/metrics,AltitudeDigital/metrics,gburton1/metrics,dropwizard/metrics,mspiegel/metrics,Banno/metrics,mveitas/metrics,gburton1/metrics,jasw/metrics,mt0803/metrics,wfxiang08/metrics,thelastpickle/metrics,dropwizard/metrics,mtakaki/metrics,egymgmbh/metrics,gorzell/metrics,mattnelson/metrics,infusionsoft/yammer-metrics,mveitas/metrics,wickedshimmy/metrics-scala,chenxianghua2014/metrics,tempredirect/metrics,infusionsoft/yammer-metrics,slovdahl/metrics,unitsofmeasurement/metrics,fcrepo4-archive/metrics,bentatham/metrics,jplock/metrics,rexren/metrics,box/metrics,ChetnaChaudhari/metrics,box/metrics,slachiewicz/metrics,ohr/metrics,fcrepo4-archive/metrics,kevintvh/metrics,valery1707/dropwizard-metrics,mnuessler/metrics,maciej/metrics-scala,erikvanoosten/metrics-scala,cirrus-dev/metrics