support nodejs 8 for a little longer

Author: monken

package.json

@@ -49,7 +49,7 @@
     "yargs": "^15.4.1"
   },
   "devDependencies": {
-    "mocha": "^8.1.3",
+    "mocha": "^7.2.0",
     "proxy-agent": "^3.1.1"
   }
 }