fix(deps): update dependency eslint-plugin-flowtype to v4

Author: renovate-bot

package-lock.json

@@ -44,7 +44,7 @@
     "@typescript-eslint/parser": "^1.13.0",
     "babel-eslint": "^10.0.2",
     "eslint-config-prettier": "^6.0.0",
-    "eslint-plugin-flowtype": "^3.13.0",
+    "eslint-plugin-flowtype": "^4.2.0",
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-jsx-a11y": "6.2.3",
     "eslint-plugin-node": "^9.1.0",