Update dependency @types/node to v14

Author: renovate-bot

package.json

@@ -59,7 +59,7 @@
     "@types/koa": "^2.11.2",
     "@types/koa-router": "^7.4.0",
     "@types/lodash": "^4.14.138",
-    "@types/node": "^12.12.26",
+    "@types/node": "14.17.3",
     "@types/request": "^2.48.4",
     "@typescript-eslint/eslint-plugin": "^2.26.0",
     "@typescript-eslint/parser": "^2.21.0",