Update Node.js to v14 (#225)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

package.json

@@ -45,7 +45,7 @@
     "child_process": false
   },
   "engines": {
-    "node": ">=10"
+    "node": ">=v14.18.1"
   },
   "testling": {
     "scripts": [