fix: upgrade bootstrap from 4.0.0-beta to 4.4.1

Snyk has created this PR to upgrade bootstrap from 4.0.0-beta to 4.4.1.

See this package in NPM:
https://www.npmjs.com/package/bootstrap

See this project in Snyk:
https://app.snyk.io/org/coderbyheart/project/a5aa72bb-b5d9-4dec-adc9-3238d3e5caa9?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/coderbyheart/underline#readme",
   "dependencies": {
-    "bootstrap": "^4.0.0-beta",
+    "bootstrap": "^4.4.1",
     "contentful": "^4.1.2",
     "font-awesome": "^4.7.0",
     "jquery": "^3.4.1",