Code review comment for lp://staging/~niedbalski/python-jujuclient/lp-1456332

Thanks guys for taking the time for reviewing.

@Tim,

I think that this is indeed a Juju-core validation error.

I submitted a PR for handling this on the server side: https://github.com/juju/juju/pull/2355

I don't think we should threat this as a special case, since this is a library and
the RPC call should warn about that. But, if you have any other idea, please let me know.

@Felipe,

I re-submitted addressing your comments adding 2 new tests.