[Security] Bump bootstrap from 3.3.6 to 4.1.2

Bumps [bootstrap](https://github.com/twbs/bootstrap) from 3.3.6 to 4.1.2. **This update includes security fixes.**
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v3.3.6...v4.1.2)

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

Author: dependabot-preview[bot]

package.json

@@ -8,7 +8,7 @@
   "license": "MIT",
   "dependencies": {
     "big.js": "^6.0.2",
-    "bootstrap": "3.3.6",
+    "bootstrap": "4.1.2",
     "bootstrap-validator": "^0.11.9",
     "clipboard": "^2.0.4",
     "jquery": "^2.2.0"

yarn.lock

@@ -10,9 +10,9 @@ bootstrap-validator@^0.11.9:
   version "0.11.9"
   resolved "https://registry.yarnpkg.com/bootstrap-validator/-/bootstrap-validator-0.11.9.tgz#fb7058eef53623e78f5aa7967026f98f875a9404"
 
-bootstrap@3.3.6:
-  version "3.3.6"
-  resolved "https://registry.yarnpkg.com/bootstrap/-/bootstrap-3.3.6.tgz#8de8f749dc8a743f2ac5b510d988371e3daa6589"
+bootstrap@4.1.2:
+  version "4.1.2"
+  resolved "https://registry.yarnpkg.com/bootstrap/-/bootstrap-4.1.2.tgz#aee2a93472e61c471fc79fb475531dcbc87de326"
 
 clipboard@^2.0.4:
   version "2.0.4"