Update dependency acorn-walk to v8

Author: renovate-bot

package.json

@@ -18,7 +18,7 @@
   },
   "homepage": "https://github.com/Rightech/node-utils#readme",
   "dependencies": {
-    "acorn-walk": "^7.2.0",
+    "acorn-walk": "^8.0.0",
     "angular-expressions": "^1.1.1",
     "colors": "^1.4.0",
     "deepmerge": "^4.2.2",