chore(package): update eslint-plugin-flowtype to version 5.0.0

Closes #12

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
     "coveralls": "^3.0.1",
     "eslint": "^6.0.1",
     "eslint-config-airbnb-base": "^13.2.0",
-    "eslint-plugin-flowtype": "^3.11.1",
+    "eslint-plugin-flowtype": "^5.0.0",
     "eslint-plugin-import": "^2.12.0",
     "husky": "^3.0.0",
     "lint-staged": "^9.1.0",