Bump bootstrap from 4.1.1 to 4.3.1

Bumps [bootstrap](https://github.com/twbs/bootstrap) from 4.1.1 to 4.3.1.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v4.1.1...v4.3.1)

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

Author: dependabot[bot]

package.json

@@ -42,7 +42,7 @@
     "travis": "gulp build:travis"
   },
   "dependencies": {
-    "bootstrap": "^4.1.1",
+    "bootstrap": "^4.3.1",
     "jquery": "^3.3.1",
     "picturefill": "^3.0.2",
     "popper.js": "^1.14.3"

yarn.lock

@@ -925,9 +925,9 @@ boolbase@^1.0.0, boolbase@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/boolbase/-/boolbase-1.0.0.tgz#68dff5fbe60c51eb37725ea9e3ed310dcc1e776e"
 
-bootstrap@^4.1.1:
-  version "4.1.1"
-  resolved "https://registry.yarnpkg.com/bootstrap/-/bootstrap-4.1.1.tgz#3aec85000fa619085da8d2e4983dfd67cf2114cb"
+bootstrap@^4.3.1:
+  version "4.3.1"
+  resolved "https://registry.yarnpkg.com/bootstrap/-/bootstrap-4.3.1.tgz#280ca8f610504d99d7b6b4bfc4b68cec601704ac"
 
 boxen@^0.5.1:
   version "0.5.1"
@@ -4873,7 +4873,7 @@ once@~1.3.0:
 
 onetime@^1.0.0:
   version "1.1.0"
-  resolved "http://registry.npmjs.org/onetime/-/onetime-1.1.0.tgz#a1f7838f8314c516f05ecefcbc4ccfe04b4ed789"
+  resolved "https://registry.npmjs.org/onetime/-/onetime-1.1.0.tgz#a1f7838f8314c516f05ecefcbc4ccfe04b4ed789"
 
 openurl@1.1.1:
   version "1.1.1"