Is upgrade-juju provider/cloud dependant?

[Curtis Hovey-Canonical]

CI tests deploy and upgrade in every CPC because I *think* these two
scenario test the provider and the streams that were placed in the
clouds. The upgrade test verifies stable juju understands the new
streams, can can upgrade to the next juju.

But does juju-upgrade have provider nuances? I don't recall seeing
upgrade fail in one provider. It fails in all, or it fails for the
same reason deploy failed. We have several tests with very slow
upgrades.

Maybe we only need one upgrade test, and CI can choose the most stable
cloud to test that on.

-- 
Curtis Hovey
Canonical Cloud Development and Operations
http://launchpad.net/~sinzui