chore(package): update sinon to version 5.0.0 (#194)

Author: greenkeeper[bot]

package.json

@@ -100,7 +100,7 @@
     "npm-run-all": "^4.1.1",
     "phantomjs-prebuilt": "^2.1.16",
     "selenium-server": "^3.8.1",
-    "sinon": "^4.0.0",
+    "sinon": "^5.0.0",
     "supertest": "^3.0.0"
   },
   "ava": {