Update babel-eslint requirement from ^8.2.6 to ^9.0.0 in /{{cookiecutter.app_name}}

Updates the requirements on [babel-eslint](https://github.com/babel/babel-eslint) to permit the latest version.
- [Release notes](https://github.com/babel/babel-eslint/releases)
- [Commits](https://github.com/babel/babel-eslint/commits/v9.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

{{cookiecutter.app_name}}/package.json

@@ -27,7 +27,7 @@
   },
   "devDependencies": {
     "babel-core": "^6.25.0",
-    "babel-eslint": "^8.2.6",
+    "babel-eslint": "^9.0.0",
     "babel-loader": "^7.0.0",
     "babel-preset-env": "^1.6.0",
     "concurrently": "^3.5.0",