fix(package): update eslint-plugin-flowtype to version 3.7.0

Closes #58

Author: greenkeeper[bot]

package.json

@@ -19,7 +19,7 @@
     "dotenv": "6.1.0",
     "eslint-config-airbnb": "17.1.0",
     "eslint-loader": "2.1.1",
-    "eslint-plugin-flowtype": "3.2.0",
+    "eslint-plugin-flowtype": "3.7.0",
     "eslint-plugin-import": "2.14.0",
     "eslint-plugin-jsx-a11y": "6.1.2",
     "eslint-plugin-react": "7.11.1",