Bump async from 2.6.3 to 2.6.4 in /samples

Bumps [async](https://github.com/caolan/async) from 2.6.3 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v2.6.3...v2.6.4)

---
updated-dependencies:
- dependency-name: async
  dependency-type: indirect
...

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

samples/package-lock.json

@@ -667,9 +667,9 @@
 			}
 		},
 		"node_modules/async": {
-			"version": "2.6.3",
-			"resolved": "https://registry.npmjs.org/async/-/async-2.6.3.tgz",
-			"integrity": "sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==",
+			"version": "2.6.4",
+			"resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+			"integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
 			"dev": true,
 			"dependencies": {
 				"lodash": "^4.17.14"
@@ -5799,9 +5799,9 @@
 			"dev": true
 		},
 		"async": {
-			"version": "2.6.3",
-			"resolved": "https://registry.npmjs.org/async/-/async-2.6.3.tgz",
-			"integrity": "sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==",
+			"version": "2.6.4",
+			"resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+			"integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
 			"dev": true,
 			"requires": {
 				"lodash": "^4.17.14"