Add regex to match branches we want to run on.

escape the forward slash

remove the slash altogether.

put slashes back

escape /

escape /'s properly.

.travis.yml

@@ -141,6 +141,6 @@ stages:
 - name: test
   if: type != cron
 - name: smoke
-  if: type NOT IN (cron, pull_request)
+  if: type NOT IN (cron, pull_request) AND (branch =~ /^(develop|master|release\/|hotfix\/)/)
 - name: update translations
   if: branch == develop AND type == cron