feat: use node 14 features

BREAKING CHANGE: only support node 14+

Author: patrickhulce

package.json

@@ -5,6 +5,9 @@
   "bin": {
     "generate-export-aliases": "./bin/generate-aliases.js"
   },
+  "engines": {
+    "node": ">=14.x.x"
+  },
   "scripts": {
     "clean": "rm -rf test/fixtures/app1/folder test/fixtures/app1/other test/fixtures/app1/path test/fixtures/app1/*.js test/fixtures/app1/*.d.ts",
     "test": "npm run test:unit",