Update async to the latest version 🚀 (#51)

* fix(package): update async to version 3.2.0

* chore(package): update lockfile package-lock.json

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: greenkeeper[bot]

package-lock.json

@@ -33,7 +33,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "async": "~3.1.0",
+    "async": "~3.2.0",
     "chalk": "~3.0.0",
     "changelog": "~1.4.2",
     "cli": "~1.0.1",