Bump debug from 2.6.3 to 2.6.9

Bumps [debug](https://github.com/visionmedia/debug) from 2.6.3 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](https://github.com/visionmedia/debug/compare/2.6.3...2.6.9)

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

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

yarn.lock

@@ -1687,13 +1687,7 @@ date-now@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/date-now/-/date-now-0.1.4.tgz#eaf439fd4d4848ad74e5cc7dbef200672b9e345b"
 
-debug@^2.1.1, debug@^2.2.0, debug@^2.6.3:
-  version "2.6.3"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.3.tgz#0f7eb8c30965ec08c72accfa0130c8b79984141d"
-  dependencies:
-    ms "0.7.2"
-
-debug@^2.6.8:
+debug@^2.1.1, debug@^2.2.0, debug@^2.6.3, debug@^2.6.8:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
   dependencies:
@@ -3918,10 +3912,6 @@ modernizr@^3.5.0:
     requirejs "2.1.22"
     yargs "7.0.2"
 
-ms@0.7.2:
-  version "0.7.2"
-  resolved "https://registry.yarnpkg.com/ms/-/ms-0.7.2.tgz#ae25cf2512b3885a1d95d7f037868d8431124765"
-
 ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"