Bump version to 0.18.0
Bump version to 0.18.0

JavierZunzunegui/prometheus,dsymonds/prometheus,slok/prometheus,AlekSi/prometheus,brancz/prometheus,GoogleCloudPlatform/prometheus,msiebuhr/prometheus,alileza/prometheus,datajet-io/prometheus,yanghongkjxy/prometheus,kzittritsch/prometheus,PrFalken/prometheus,kzittritsch/prometheus,amorken/prometheus,gottwald/prometheus,GoogleCloudPlatform/prometheus,Conorbro/prometheus,SaltedMan/prometheus-annotated,alileza/prometheus,GoogleCloudPlatform/prometheus,dmilstein/prometheus,AlekSi/prometheus,SaltedMan/prometheus-annotated,PrFalken/prometheus,kangwoo/prometheus,yanghongkjxy/prometheus,Colstuwjx/prometheus,tattsun/prometheus,alileza/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,yanghongkjxy/prometheus,msiebuhr/prometheus,adamron1/prometheus,kzittritsch/prometheus,msiebuhr/prometheus,tattsun/prometheus,SaltedMan/prometheus-annotated,agaoglu/prometheus,dsymonds/prometheus,keegancsmith/prometheus,slok/prometheus,dsymonds/prometheus,datajet-io/prometheus,agaoglu/prometheus,ton31337/prometheus,GoogleCloudPlatform/prometheus,dsymonds/prometheus,brancz/prometheus,prometheus/prometheus,PrFalken/prometheus,Stackdriver/stackdriver-prometheus,AlekSi/prometheus,dmilstein/prometheus,sudhi-vm/prometheus,Stackdriver/stackdriver-prometheus,tomwilkie/prometheus,amorken/prometheus,prometheus/prometheus,JavierZunzunegui/prometheus,Colstuwjx/prometheus,Stackdriver/stackdriver-prometheus,prometheus/prometheus,datajet-io/prometheus,kangwoo/prometheus,tomwilkie/prometheus,tattsun/prometheus,adamron1/prometheus,keegancsmith/prometheus,yanghongkjxy/prometheus,prometheus/prometheus,keegancsmith/prometheus,amorken/prometheus,sudhi-vm/prometheus,datajet-io/prometheus,Gouthamve/prometheus,ton31337/prometheus,brancz/prometheus,ton31337/prometheus,Gouthamve/prometheus,tomwilkie/prometheus,dmilstein/prometheus,SaltedMan/prometheus-annotated,PrFalken/prometheus,agaoglu/prometheus,kangwoo/prometheus,gottwald/prometheus,adamron1/prometheus,msiebuhr/prometheus,amorken/prometheus,JavierZunzunegui/prometheus,sudhi-vm/prometheus,gottwald/prometheus,slok/prometheus,alileza/prometheus,tattsun/prometheus,agaoglu/prometheus,Conorbro/prometheus,AlekSi/prometheus,kangwoo/prometheus,slok/prometheus,Stackdriver/stackdriver-prometheus,tomwilkie/prometheus,adamron1/prometheus,dmilstein/prometheus,keegancsmith/prometheus,sudhi-vm/prometheus,prometheus/prometheus,ton31337/prometheus,gottwald/prometheus,Conorbro/prometheus,Colstuwjx/prometheus,Colstuwjx/prometheus,kzittritsch/prometheus,JavierZunzunegui/prometheus,keegancsmith/prometheus,alileza/prometheus,brancz/prometheus,Gouthamve/prometheus,Conorbro/prometheus