Merge pull request #2331 from cjdcordeiro/update-ubuntu-maintainers

Update Ubuntu's maintainer.md

ubuntu/maintainer.md

@@ -1 +1 @@
-[Canonical](https://launchpad.net/cloud-images) and [Tianon (Debian Developer)](%%GITHUB-REPO%%)
+[Canonical](https://launchpad.net/cloud-images)