append metric instance to resource so that de-dup works as expected
Merge pull request #11 from guardian/ns-metric-instance

Append metric instance to resource so that de-dup works as expected
Change % to perc to prevent potential problems with future versions of Clojure using % as a macro character.
Merge branch 'master' of github.com:robertberry/riemann-config into ios-purchases-alerts
Use coalesce-stream instead of fixed-time-window for calculating the % of 500s in the iOS Purchases alerts.