Remove acorn from top level package dependency

Author: deleonn

package-lock.json

@@ -46,7 +46,6 @@
   ],
   "license": "Apache-2.0",
   "devDependencies": {
-    "acorn": "^8.7.1",
     "babel-cli": "^6.9.0",
     "babel-eslint": "^6.0.4",
     "babel-plugin-add-module-exports": "^0.1.2",