chore(package): update sinon to version 8.0.0

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
     "husky": "^2.5.0",
     "nyc": "^14.1.1",
     "rimraf": "^2.5.4",
-    "sinon": "^7.3.2",
+    "sinon": "^8.0.0",
     "validate-commit-msg": "^2.8.2"
   },
   "ava": {