Backport fix for replicaset startup from trunk
Merge pull request #467 from wallyworld/backport-replicaset-startup

Backport fix for replicaset startup from trunk

Done mainly to use longer 60s timeout, but also brings 1.20 implementation in line with trunk.
MAAS provider uses hostname as cloud local address
Extra comment
Merge pull request #473 from wallyworld/maas-hostname-address

MAAS provider uses hostname as cloud local address

The MAAS provider inserts a cloud local address equal to the dns name into the list of addresses returned by the instance.

Fixes: https://bugs.launchpad.net/juju-core/+bug/1353442
Bump version to 1.20.4
Merge pull request #475 from wallyworld/bump-to-1.20.4

Bump version to 1.20.4