create a validator module for argparse

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
add tests for the new regex validator

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
create a Hostname validator

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
tests for the new hostname validator

Signed-off-by: Alfredo Deza <alfredo@deza.pe>

improve wording of IP error

Signed-off-by: Alfredo Deza <alfredo@deza.pe>

update tests for the new wording

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
use an arg validator in new mon to prevent passing an IP

Signed-off-by: Alfredo Deza <alfredo@deza.pe>

use the new hostname validator

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
patch socket on tests that call cli directly
Merge pull request #29 from alfredodeza/5763

Prevent passing an IP to `ceph-deploy new`
Reviewed-by: Dan Mick <dan.mick@inktank.com>