Bump async from 2.6.2 to 2.6.4 in /example

Bumps [async](https://github.com/caolan/async) from 2.6.2 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](caolan/async@v2.6.2...v2.6.4)

---
updated-dependencies:
- dependency-name: async
  dependency-type: indirect
...

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

Author: dependabot[bot]

example/package-lock.json

@@ -796,10 +796,10 @@ async-limiter@~1.0.0:
   resolved "https://registry.yarnpkg.com/async-limiter/-/async-limiter-1.0.0.tgz#78faed8c3d074ab81f22b4e985d79e8738f720f8"
 
 async@^2.4.0, async@^2.6.1:
-  version "2.6.2"
-  resolved "https://registry.yarnpkg.com/async/-/async-2.6.2.tgz#18330ea7e6e313887f5d2f2a904bac6fe4dd5381"
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.4.tgz#706b7ff6084664cd7eae713f6f965433b5504221"
   dependencies:
-    lodash "^4.17.11"
+    lodash "^4.17.14"
 
 asynckit@^0.4.0:
   version "0.4.0"
@@ -2913,7 +2913,7 @@ lodash.throttle@^4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/lodash.throttle/-/lodash.throttle-4.1.1.tgz#c23e91b710242ac70c37f1e1cda9274cc39bf2f4"
 
-lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.5, lodash@^4.3.0, lodash@^4.6.1:
+lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.14, lodash@^4.17.5, lodash@^4.3.0, lodash@^4.6.1:
   version "4.17.21"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"