Update bourbon-neat requirement from ~1.9 to ~4.0

Updates the requirements on [bourbon-neat](https://github.com/thoughtbot/neat) to permit the latest version.
- [Release notes](https://github.com/thoughtbot/neat/releases)
- [Changelog](https://github.com/thoughtbot/neat/blob/master/CHANGELOG.md)
- [Commits](thoughtbot/neat@v1.9.0...v4.0.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -10,7 +10,7 @@
   "dependencies": {},
   "devDependencies": {
     "bourbon": "~4.3",
-    "bourbon-neat": "~1.9",
+    "bourbon-neat": "~4.0",
     "css-loader": "^2.1.1",
     "file-loader": "^3.0.1",
     "font-awesome": "^4.7.0",