chore(package): update sinon to version 1.17.6

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -57,7 +57,7 @@
     "nyc": "^8.1.0",
     "q": "~1.4.1",
     "rsvp": "^3.2.1",
-    "sinon": "1.17.5",
+    "sinon": "1.17.6",
     "updtr": "^0.2.1"
   }
 }