Bump js-yaml from 3.12.2 to 3.13.1 in /example (#283)

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.12.2 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@3.12.2...3.13.1)

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

example/yarn.lock

@@ -4132,9 +4132,9 @@ js-tokens@^3.0.2:
   integrity sha1-mGbfOVECEw449/mWvOtlRDIJwls=
 
 js-yaml@^3.12.0, js-yaml@^3.7.0, js-yaml@^3.9.0:
-  version "3.12.2"
-  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.12.2.tgz#ef1d067c5a9d9cb65bd72f285b5d8105c77f14fc"
-  integrity sha512-QHn/Lh/7HhZ/Twc7vJYQTkjuCa0kaCcDcjK5Zlk2rvnUpy7DxMJ23+Jc2dcyvltwQVg1nygAVlB2oRDFHoRS5Q==
+  version "3.13.1"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.13.1.tgz#aff151b30bfdfa8e49e05da22e7415e9dfa37847"
+  integrity sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==
   dependencies:
     argparse "^1.0.7"
     esprima "^4.0.0"