Fix TestKit backend startup for nodejs >10 (#996)

Co-authored-by: Antonio Barcelos <[email protected]>

Author: robsdedude

packages/testkit-backend/package.json

@@ -11,7 +11,7 @@
   "type": "module",
   "scripts": {
     "build": "rollup src/index.js --config rollup.config.js",
-    "start": "node -r esm src/index.js",
+    "start": "node --version | grep -q v10. && node -r esm src/index.js || node --experimental-specifier-resolution=node src/index.js",
     "clean": "rm -fr node_modules public/index.js",
     "prepare": "npm run build"
   },