chore(package): update sinon to version 8.0.0

Closes #11

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
     "eslint-plugin-promise": "^3.6.0",
     "eslint-plugin-standard": "^3.0.1",
     "mocha": "^5.0.0",
-    "sinon": "^5.0.0",
+    "sinon": "^8.0.0",
     "uuid-validate": "0.0.2"
   },
   "dependencies": {