[Security] Bump bootstrap-sass from 3.4.0 to 3.4.1

Bumps [bootstrap-sass](https://github.com/twbs/bootstrap-sass) from 3.4.0 to 3.4.1. **This update includes security fixes.**
- [Release notes](https://github.com/twbs/bootstrap-sass/releases)
- [Changelog](https://github.com/twbs/bootstrap-sass/blob/master/CHANGELOG.md)
- [Commits](https://github.com/twbs/bootstrap-sass/compare/v3.4.0...v3.4.1)

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

package.json

@@ -13,7 +13,7 @@
     "animate-sass": "^0.8.2",
     "autosize": "^3.0.20",
     "axios": "^0.18",
-    "bootstrap-sass": "^3.3.6",
+    "bootstrap-sass": "^3.4.1",
     "chart.js": "^2.7.0",
     "cross-env": "^5.1",
     "es5-shim": "^4.5.9",