chore(travis): whitelist greenkeeper branches

greenkeeper[bot] · greenkeeper[bot] · commit a879d4cdf24e · 2017-07-26T04:17:26.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -23,4 +23,4 @@ after_success:
   - npm run ngh
 branches:
   only:
-  - master
+  - master  - /^greenkeeper/.*$/
