chore(deps): bump async from 2.6.3 to 2.6.4

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>

package-lock.json

@@ -1559,6 +1559,15 @@
       "resolved": "https://registry.npmjs.org/ast-types/-/ast-types-0.9.6.tgz",
       "integrity": "sha1-ECyenpAF0+fjgpvwxPok7oYu6bk="
     },
+    "async": {
+      "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"
+      }
+    },
     "async-each": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/async-each/-/async-each-1.0.3.tgz",
@@ -5745,15 +5754,6 @@
         "mkdirp": "^0.5.5"
       },
       "dependencies": {
-        "async": {
-          "version": "2.6.3",
-          "resolved": "https://registry.npmjs.org/async/-/async-2.6.3.tgz",
-          "integrity": "sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==",
-          "dev": true,
-          "requires": {
-            "lodash": "^4.17.14"
-          }
-        },
         "debug": {
           "version": "3.2.7",
           "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.7.tgz",