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](nodeca/js-yaml@3.12.0...3.13.1)

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

Author: dependabot[bot]

package-lock.json

@@ -11,7 +11,7 @@
     "test"
   ],
   "dependencies": {
-    "js-yaml": "^3.12.0",
+    "js-yaml": "^3.13.1",
     "mocha": "^5.2.0",
     "rimraf": "^2.6.2"
   },