Merge pull request #948 from graphql/greenkeeper/flow-bin-0.50.0

Update flow-bin to the latest version 🚀

Author: wincent

package.json

@@ -56,7 +56,7 @@
     "eslint": "4.2.0",
     "eslint-plugin-babel": "4.1.1",
     "eslint-plugin-flowtype": "2.35.0",
-    "flow-bin": "0.49.1",
+    "flow-bin": "0.50.0",
     "isparta": "4.0.0",
     "mocha": "3.4.2",
     "sane": "2.0.0"