chore(deps): update dependency acorn to ^7.4.1 (#128)

Co-authored-by: Renovate Bot <[email protected]>

Author: renovate[bot]

package-lock.json

@@ -19,7 +19,7 @@
     "estraverse": "^4.3.0"
   },
   "devDependencies": {
-    "acorn": "^7.1.1",
+    "acorn": "^7.4.1",
     "eslint": "^6.8.0",
     "eslint-config-teppeis": "^10.3.1",
     "espurify": "^2.0.1",