fix(deps): update dependency async to v2.6.4 [security]

Author: renovate[bot]

package.json

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "algoliasearch": "3.33.0",
-    "async": "2.6.3",
+    "async": "2.6.4",
     "babel-eslint": "8.2.6",
     "babel-loader": "8.0.6",
     "critical": "1.3.4",