setup() is noisy

[Stuart Bishop]

The deployer.setup() method invokes juju-deployer with the '-W' option, which creates several lines out output.

While sometimes this is wanted, if you are using a more complex test framework this noise gets interleaved with the output making it unreadable.

It would be lovely if there was an option to turn this off and not use the '-W' flag.

[Stuart Bishop (stub)]

Alternatively, capture stdout and stderr and only emit them if the command failed.