Manager._list should always return a list
Manager._list should always return a list

Convert single-row result sets to dicts for consistent
handling of single-element lists.

Change-Id: I2fc88743f8cee0112211cd837bbfcb7d95753d3d

citrix-openstack-build/python-ironicclient,bcrochet/python-ironicclient,varunarya10/python-ironicclient,openstack/python-ironicclient,redhat-openstack/python-ironicclient,JioCloud/python-ironicclient,openstack/python-ironicclient,CiscoUcs/UCS-python-ironicclinet,NaohiroTamura/python-ironicclient,ramineni/myclient,rdo-management/python-ironicclient,NaohiroTamura/python-ironicclient