[Security] Bump acorn from 5.7.3 to 5.7.4

Bumps [acorn](https://github.com/acornjs/acorn) from 5.7.3 to 5.7.4. **This update includes a security fix.**
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/5.7.3...5.7.4)

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

package-lock.json

@@ -667,9 +667,9 @@
       }
     },
     "acorn": {
-      "version": "5.7.3",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
-      "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==",
+      "version": "5.7.4",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.4.tgz",
+      "integrity": "sha512-1D++VG7BhrtvQpNbBzovKNc1FLGGEE/oGe7b9xJm/RFHMBeUaUGpluV9RLjZa47YFdPcDAenEYuq9pQPcMdLJg==",
       "dev": true
     },
     "acorn-dynamic-import": {
@@ -692,9 +692,9 @@
       },
       "dependencies": {
         "acorn": {
-          "version": "6.1.1",
-          "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.1.1.tgz",
-          "integrity": "sha512-jPTiwtOxaHNaAPg/dmrJ/beuzLRnXtB0kQPQ8JpotKJgTB6rX6c8mlf315941pyjBSaPg8NHXS9fhP4u17DpGA==",
+          "version": "6.4.1",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.4.1.tgz",
+          "integrity": "sha512-ZVA9k326Nwrj3Cj9jlh3wGFutC2ZornPNARZwsNYqQYgN0EsV2d53w5RN/co65Ohn4sUAUtb1rSUAOD6XN9idA==",
           "dev": true
         }
       }