hca: Add hostname command
hca: Add hostname command

hostname is 28k and has no dependencies.
Add it as a convenient command.

Change-Id: I979431e849d208d257731b275d716dbffdb0845f
Signed-off-by: Spyros Trigazis <1e6dbf5402ced737cda15d668682ea874352489e@cern.ch>

ArchiFleKs/magnum,ArchiFleKs/magnum,openstack/magnum,openstack/magnum