Bump acorn from 6.1.1 to 6.4.1

Bumps [acorn](https://github.com/acornjs/acorn) from 6.1.1 to 6.4.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.1.1...6.4.1)

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

package-lock.json

@@ -1,6 +1,6 @@
 {
 	"name": "contact",
-	"version": "1.0.1",
+	"version": "2.0.0",
 	"lockfileVersion": 1,
 	"requires": true,
 	"dependencies": {
@@ -22,9 +22,9 @@
 			}
 		},
 		"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
 		},
 		"acorn-jsx": {