Only send email notifications on failure
Only send email notifications on failure

Getting an email every time you push a passing commit can get
frustrating. The interface lets you know anyway so only notify on
failure. This matches the way that we have our internal CI setup.

quis/govuk_template,froddd/govuk_template,jonheslop/govuk_template,quis/govuk_template,robinwhittleton/govuk_template,froddd/govuk_template,froddd/govuk_template,robinwhittleton/govuk_template,robinwhittleton/govuk_template,alphagov/govuk_template,alphagov/govuk_template,froddd/govuk_template,jonheslop/govuk_template,quis/govuk_template,froddd/govuk_template,robinwhittleton/govuk_template,jonheslop/govuk_template,jonheslop/govuk_template,alphagov/govuk_template,jonheslop/govuk_template,alphagov/govuk_template,robinwhittleton/govuk_template,quis/govuk_template,alphagov/govuk_template,quis/govuk_template