chore(package): update yargs to version 4.3.1

http://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -6,7 +6,7 @@
   "bin": "src/cli.js",
   "dependencies": {
     "react": "~0.14.6",
-    "yargs": "~3.32.0",
+    "yargs": "~4.3.1",
     "jsdom-no-contextify": "~3.1.0"
   },
   "devDependencies": {