chore(deps): update dependency mocha to v6 (#217)

Author: renovate[bot]

monitoring/snippets/package.json

@@ -20,7 +20,7 @@
   "devDependencies": {
     "chai": "^4.2.0",
     "execa": "^1.0.0",
-    "mocha": "^5.0.0",
+    "mocha": "^6.0.0",
     "p-retry": "^3.0.0",
     "uuid": "^3.3.2"
   }