Merge pull request #494 from cfchou/dev_160401

pinning node_redis to 2.5.x

package.json

@@ -100,7 +100,7 @@
     "leveldown": "~1.4.3",
     "zmq": "~2.15.0",
     "amqp": "~0.2.4",
-    "redis": "~2.6.0-2",
+    "redis": "~2.5.0",
     "hiredis": "^0.4.1",
     "mongodb": "~2.1.4"
   }