realmd: do not depend on pywbem

Fallback to pywbem only if wbem is not available.

Signed-off-by: Michal Minar <miminar@redhat.com>
selinux: use rtd theme for documentation

Signed-off-by: Michal Minar <miminar@redhat.com>
prepare new release 0.4.0

Signed-off-by: Michal Minar <miminar@redhat.com>