Bump js-yaml from 3.12.0 to 3.13.1

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.12.0 to 3.13.1.
- [Release notes](https://github.com/nodeca/js-yaml/releases)
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nodeca/js-yaml/compare/3.12.0...3.13.1)

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

package.json

@@ -28,7 +28,7 @@
   },
   "dependencies": {
     "font-awesome": "4.7.0",
-    "js-yaml": "3.12.0",
+    "js-yaml": "3.13.1",
     "material-design-icons": "3.0.1",
     "material-icons": "0.2.3",
     "npm-font-open-sans": "1.1.0",