Dimension value list doesn't recognize dimension name input
Dimension value list doesn't recognize dimension name input

When using CLI to query dimension value list,
monasca dimension-value-list --metric-name cpu.user_perc hostname
'Namespace' object has no attribute 'dimension_name'

The attribute name was 'dimension-name' instead of 'dimension_name'

Change-Id: I826fa95beafa106bbc7189928d258302fb288c44

stackforge/python-monascaclient,sapcc/python-monascaclient,stackforge/python-monascaclient,openstack/python-monascaclient,openstack/python-monascaclient,sapcc/python-monascaclient