Increase waiting time in TestEvictAndLoadChunkDescs
Increase waiting time in TestEvictAndLoadChunkDescs

The test had become flaky with Go1.5.

Theory here is that with Go1.5.x, sleeping for 10ms might not be
enough to wake up another goroutine, possibly because it is used for
GC. 50ms should always be enough due to GC pause guarantees with the
new GC.

Stackdriver/stackdriver-prometheus,Gouthamve/prometheus,prometheus/prometheus,thachmai/prometheus,dsymonds/prometheus,alileza/prometheus,msiebuhr/prometheus,brancz/prometheus,GoogleCloudPlatform/prometheus,gottwald/prometheus,wrouesnel/prometheus,JavierZunzunegui/prometheus,alileza/prometheus,dsymonds/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,tattsun/prometheus,gottwald/prometheus,thachmai/prometheus,Colstuwjx/prometheus,agaoglu/prometheus,prometheus/prometheus,ton31337/prometheus,alileza/prometheus,kangwoo/prometheus,sudhi-vm/prometheus,wrouesnel/prometheus,dmilstein/prometheus,brancz/prometheus,adamron1/prometheus,ton31337/prometheus,adamron1/prometheus,Gouthamve/prometheus,Gouthamve/prometheus,Colstuwjx/prometheus,yanghongkjxy/prometheus,tattsun/prometheus,Gouthamve/prometheus,jbdalido/prometheus,agaoglu/prometheus,iksaif/prometheus,dsymonds/prometheus,amorken/prometheus,Conorbro/prometheus,prometheus/prometheus,kzittritsch/prometheus,tomwilkie/prometheus,trigrass2/prometheus,amorken/prometheus,RobertKielty/prometheus,Stackdriver/stackdriver-prometheus,thachmai/prometheus,msiebuhr/prometheus,keegancsmith/prometheus,mtanda/prometheus,slok/prometheus,dln/prometheus,jbdalido/prometheus,gcnonato/prometheus,gottwald/prometheus,Colstuwjx/prometheus,wrouesnel/prometheus,gcnonato/prometheus,dln/prometheus,JavierZunzunegui/prometheus,kzittritsch/prometheus,eliothedeman/prometheus,iksaif/prometheus,RobertKielty/prometheus,sudhi-vm/prometheus,dmilstein/prometheus,PrFalken/prometheus,AlekSi/prometheus,dmilstein/prometheus,dln/prometheus,GoogleCloudPlatform/prometheus,jbdalido/prometheus,prometheus/prometheus,sudhi-vm/prometheus,msiebuhr/prometheus,dsymonds/prometheus,slok/prometheus,JavierZunzunegui/prometheus,datajet-io/prometheus,gcnonato/prometheus,msiebuhr/prometheus,tattsun/prometheus,AlekSi/prometheus,PrFalken/prometheus,thachmai/prometheus,kangwoo/prometheus,gcnonato/prometheus,eliothedeman/prometheus,RobertKielty/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,trigrass2/prometheus,kangwoo/prometheus,datajet-io/prometheus,mtanda/prometheus,adamron1/prometheus,brancz/prometheus,Stackdriver/stackdriver-prometheus,iksaif/prometheus,eliothedeman/prometheus,agaoglu/prometheus,slok/prometheus,keegancsmith/prometheus,AlekSi/prometheus,PrFalken/prometheus,mtanda/prometheus,AlekSi/prometheus,JavierZunzunegui/prometheus,SaltedMan/prometheus-annotated,trigrass2/prometheus,PrFalken/prometheus,slok/prometheus,brancz/prometheus,sudhi-vm/prometheus,Conorbro/prometheus,eliothedeman/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,amorken/prometheus,gottwald/prometheus,wrouesnel/prometheus,tomwilkie/prometheus,mtanda/prometheus,yanghongkjxy/prometheus,Colstuwjx/prometheus,GoogleCloudPlatform/prometheus,SaltedMan/prometheus-annotated,prometheus/prometheus,datajet-io/prometheus,trigrass2/prometheus,iksaif/prometheus,adamron1/prometheus,kzittritsch/prometheus,tattsun/prometheus,dln/prometheus,kzittritsch/prometheus,jbdalido/prometheus,ton31337/prometheus,dmilstein/prometheus,datajet-io/prometheus,SaltedMan/prometheus-annotated,Conorbro/prometheus,SaltedMan/prometheus-annotated,tomwilkie/prometheus,RobertKielty/prometheus,agaoglu/prometheus,Stackdriver/stackdriver-prometheus,alileza/prometheus,yanghongkjxy/prometheus,amorken/prometheus,tomwilkie/prometheus,kangwoo/prometheus,Conorbro/prometheus,yanghongkjxy/prometheus,ton31337/prometheus