chore(package): update msgflo to version 0.12.1

Closes #19

Author: greenkeeper[bot]

package.json

@@ -31,6 +31,6 @@
     "mocha": "^5.0.0",
     "amqplib": "^0.5.1",
     "mqtt": "^2.13.0",
-    "msgflo": "^0.11.0"
+    "msgflo": "^0.12.1"
   }
 }