fix(package): update eslint-plugin-flowtype to version 4.5.0

Closes #23

Author: greenkeeper[bot]

package.json

@@ -19,7 +19,7 @@
     "eslint": "^4.5.0",
     "eslint-config-airbnb": "^16.1.0",
     "eslint-config-prettier": "^2.6.0",
-    "eslint-plugin-flowtype": "^2.35.0",
+    "eslint-plugin-flowtype": "^4.5.0",
     "eslint-plugin-import": "^2.7.0",
     "eslint-plugin-jsx-a11y": "^6.0.2",
     "eslint-plugin-prettier": "^2.2.0",