CI hates juju, maybe the feelings are mutual

[Curtis Hovey-Canonical]

Here is the summary of what is happening:

Two different bugs in devel and stable branches have broken a common
Juju CI test.

- devel (trunk) is broken by r2593 [The machine agent is now
responsible for setting up mongo.] Upgrades timeout or fail because
API server is down for many minutes.

- stable (1.18) is broken by r2264 [worker/upgrader: Refuse to
downgrade]. It is not possible to test upgrades from 1.18.0 to 1.18.1
because juju 1.18.0 client is deploying juju 1.18.1. The test was
using downgrade to ensure there was something to upgrade.

Release 1.19.0 and 1.18.1 are stalled waiting for resolution.

- Option 1 revert the revisions that break CI

- Option 2 fix the issues with a new revision

- Option 3 Change CI to work with the new behaviours.

Will will try option 3 first:

- devel: change the tests to try for 30 minutes and forgive the api
server for being down for many minutes. If 30 minutes is not enough
time to upgrade, this is a bug that needs fixing.
  - Note that Aaron was working on a pair of test charms that give
    CI more information.

- stable: change the test to bootstrap with the released streams, then
use set-env to point tools-metadata-url to the new testing streams,
finally call juju-upgrade. If this fails...
 - Bug #1247232: Juju client deploys agent newer than itself
<https://launchpad.net/bugs/1247232> will be fixed sooner rather than
later. but as it is targeted to 1.19.0, sooner is still in the next
few weeks.

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