Bump acorn from 7.0.0 to 7.1.1

Bumps [acorn](https://github.com/acornjs/acorn) from 7.0.0 to 7.1.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/7.0.0...7.1.1)

Signed-off-by: dependabot[bot] <support@github.com>

package-lock.json

@@ -424,9 +424,9 @@
       "dev": true
     },
     "acorn": {
-      "version": "7.0.0",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-7.0.0.tgz",
-      "integrity": "sha512-PaF/MduxijYYt7unVGRuds1vBC9bFxbNf+VWqhOClfdgy7RlVkQqt610ig1/yxTgsDIfW1cWDel5EBbOy3jdtQ==",
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-7.1.1.tgz",
+      "integrity": "sha512-add7dgA5ppRPxCFJoAGfMDi7PIBXq1RtGo7BhbLaxwrXPOmw8gq48Y9ozT01hUKy9byMjlR20EJhu5zlkErEkg==",
       "dev": true
     },
     "acorn-jsx": {