Update eslint-plugin-flowtype to the latest version 🚀 (#1125)

* chore(package): update eslint-plugin-flowtype to version 4.7.0

* chore(package): update lockfile package-lock.json

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: greenkeeper[bot]

package-lock.json

@@ -56,7 +56,7 @@
     "core-js": "3.6.1",
     "cross-env": "7.0.2",
     "eslint": "6.8.0",
-    "eslint-plugin-flowtype": "4.5.2",
+    "eslint-plugin-flowtype": "4.7.0",
     "express": "4.17.1",
     "gulp": "4.0.2",
     "gulp-babel": "8.0.0",