Bump bootstrap-sass from 3.4.1 to 3.4.3

Bumps [bootstrap-sass](https://github.com/twbs/bootstrap-sass) from 3.4.1 to 3.4.3.
- [Release notes](https://github.com/twbs/bootstrap-sass/releases)
- [Changelog](https://github.com/twbs/bootstrap-sass/blob/master/CHANGELOG.md)
- [Commits](twbs/bootstrap-sass@v3.4.1...v3.4.3)

---
updated-dependencies:
- dependency-name: bootstrap-sass
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package.json

@@ -47,7 +47,7 @@
     "@ember/jquery": "^1.1",
     "@ember/optional-features": "^2.0.0",
     "bootstrap": "3.4.1",
-    "bootstrap-sass": "3.4.1",
+    "bootstrap-sass": "3.4.3",
     "bootswatch": "^3.3.7",
     "broccoli-asset-rev": "^3.0.0",
     "ember-cli": "~3.10.1",

yarn.lock

@@ -2578,10 +2578,10 @@ boom@2.x.x:
   dependencies:
     hoek "2.x.x"
 
-bootstrap-sass@3.4.1:
-  version "3.4.1"
-  resolved "https://registry.yarnpkg.com/bootstrap-sass/-/bootstrap-sass-3.4.1.tgz#6843c73b1c258a0ac5cb2cc6f6f5285b664a8e9a"
-  integrity sha512-p5rxsK/IyEDQm2CwiHxxUi0MZZtvVFbhWmyMOt4lLkA4bujDA1TGoKT0i1FKIWiugAdP+kK8T5KMDFIKQCLYIA==
+bootstrap-sass@3.4.3:
+  version "3.4.3"
+  resolved "https://registry.yarnpkg.com/bootstrap-sass/-/bootstrap-sass-3.4.3.tgz#742cc8f4286303ae9fe8e4c95237321eae73766c"
+  integrity sha512-vPgFnGMp1jWZZupOND65WS6mkR8rxhJxndT/AcMbqcq1hHMdkcH4sMPhznLzzoHOHkSCrd6J9F8pWBriPCKP2Q==
 
 bootstrap@3.4.1:
   version "3.4.1"