chore(deps): update dependency sinon to v8

Author: renovate-bot

package-lock.json

@@ -136,7 +136,7 @@
     "nodemon": "2.0.2",
     "nyc": "14.1.1",
     "prettier": "1.19.1",
-    "sinon": "7.5.0",
+    "sinon": "8.0.0",
     "sinon-chai": "3.3.0",
     "socket.io-client": "2.3.0",
     "supertest": "4.0.2",