test_driver: implement virDomainGetHostname
test_driver: implement virDomainGetHostname

Always return "domain_name" + "host".

Signed-off-by: Ilias Stamatis <3ef66acc2700f2eb6746a592b321628ebd41accf@gmail.com>
Reviewed-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>

fabianfreyer/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,jfehlig/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,olafhering/libvirt,eskultety/libvirt,libvirt/libvirt,nertpinx/libvirt,zippy2/libvirt,fabianfreyer/libvirt,zippy2/libvirt,nertpinx/libvirt,eskultety/libvirt,jardasgit/libvirt,crobinso/libvirt,nertpinx/libvirt,nertpinx/libvirt,andreabolognani/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt,jfehlig/libvirt,jardasgit/libvirt,crobinso/libvirt,jardasgit/libvirt,olafhering/libvirt,fabianfreyer/libvirt,zippy2/libvirt,libvirt/libvirt,andreabolognani/libvirt,libvirt/libvirt,eskultety/libvirt,eskultety/libvirt,crobinso/libvirt,andreabolognani/libvirt,jardasgit/libvirt,crobinso/libvirt,eskultety/libvirt,olafhering/libvirt,olafhering/libvirt,andreabolognani/libvirt,libvirt/libvirt,jardasgit/libvirt