Upgrade: Bump debug from 2.6.8 to 2.6.9

Bumps [debug](https://github.com/visionmedia/debug) from 2.6.8 to 2.6.9.
- [Release notes](https://github.com/visionmedia/debug/releases)
- [Changelog](https://github.com/visionmedia/debug/blob/2.6.9/CHANGELOG.md)
- [Commits](debug-js/debug@2.6.8...2.6.9)

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

yarn.lock

@@ -1171,8 +1171,8 @@ dateformat@^1.0.11, dateformat@^1.0.12:
     meow "^3.3.0"
 
 debug@^2.1.1, debug@^2.2.0:
-  version "2.6.8"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.8.tgz#e731531ca2ede27d188222427da17821d68ff4fc"
+  version "2.6.9"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
   dependencies:
     ms "2.0.0"