Merge pull request #12 from greenkeeperio/greenkeeper/rollbar-2.3.9

chore(package): update rollbar to version 2.3.9

Author: hulkoba

package.json

@@ -10,7 +10,7 @@
     "normalize-registry-metadata": "^1.1.2",
     "redis": "^2.6.2",
     "request": "^2.75.0",
-    "rollbar": "^2.0.1"
+    "rollbar": "^2.3.9"
   },
   "devDependencies": {
     "nock": "^9.0.13",