Update css-loader requirement to ^1.0.0 in /{{cookiecutter.app_name}}

Updates the requirements on [css-loader](https://github.com/webpack-contrib/css-loader) to permit the latest version.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/css-loader/commits/v1.0.0)

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

{{cookiecutter.app_name}}/package.json

@@ -31,7 +31,7 @@
     "babel-loader": "^7.0.0",
     "babel-preset-env": "^1.6.0",
     "concurrently": "^3.5.0",
-    "css-loader": "^0.28.4",
+    "css-loader": "^1.0.0",
     "eslint": "^3.19.0",
     "eslint-config-airbnb-base": "^11.2.0",
     "eslint-plugin-import": "^2.3.0",