Bump bootstrap from 4.1.2 to 4.3.1

Bumps [bootstrap](https://github.com/twbs/bootstrap) from 4.1.2 to 4.3.1.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v4.1.2...v4.3.1)

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

Author: dependabot[bot]

package-lock.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "dependencies": {
-    "bootstrap": "^4.1.2",
+    "bootstrap": "^4.3.1",
     "pretty-json-stringify": "0.0.2",
     "prettyjson": "^1.2.1",
     "shpjs": "^3.4.2"