Added task to retrieve numbers of errors from sentry
merged master
refactored ContentPerformanceController
merged master and resolved conflicts
Merge remote-tracking branch 'origin/master' into gallery-sentry-dashboard
tidy: remove extranous logging and method paramaters
Merge remote-tracking branch 'origin/master' into gallery-sentry-dashboard
removed inadvertent indenting and unused trait
Merge pull request #5917 from guardian/gallery-sentry-dashboard

Gallery sentry dashboard