chore(deps-dev): bump acorn from 6.2.0 to 6.2.1

Bumps [acorn](https://github.com/acornjs/acorn) from 6.2.0 to 6.2.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.2.0...6.2.1)

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

web3.js/package-lock.json

@@ -4206,9 +4206,9 @@
       }
     },
     "acorn": {
-      "version": "6.2.0",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.2.0.tgz",
-      "integrity": "sha512-8oe72N3WPMjA+2zVG71Ia0nXZ8DpQH+QyyHO+p06jT8eg8FGG3FbcUIi8KziHlAfheJQZeoqbvq1mQSQHXKYLw==",
+      "version": "6.2.1",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.2.1.tgz",
+      "integrity": "sha512-JD0xT5FCRDNyjDda3Lrg/IxFscp9q4tiYtxE1/nOzlKCk7hIRuYjhq1kCNkbPjMRMZuFq20HNQn1I9k8Oj0E+Q==",
       "dev": true
     },
     "acorn-globals": {