Use auth_token middleware in keystoneclient.
Use auth_token middleware in keystoneclient.

The auth_token middleware moved into keystoneclient so a full
keystone install is not required to use the middleware.Also
add missing signing_dir to api-paste.ini.

Change-Id: If6c339045b70b3d4d70f0297ec32ed3cfdf431de

gandelman-a/neutron-lbaas,citrix-openstack-build/neutron-vpnaas,dougwig/x-neutron-fwaas,dougwig/x-neutron-lbaas,openstack/neutron-vpnaas,flavio-fernandes/networking-odl,citrix-openstack-build/neutron-fwaas,dougwig/x-neutron-vpnaas,openstack/neutron-vpnaas,FedericoRessi/networking-odl,mestery/x-stackforge-odl,openstack/networking-odl,schoksey/networking-odl,openstack/neutron-fwaas,gandelman-a/neutron-lbaas,gaolichuang/neutron-fwaas,flavio-fernandes/networking-odl,gotostack/neutron-lbaas,schoksey/networking-odl,gandelman-a/neutron-lbaas,citrix-openstack-build/neutron-lbaas,gotostack/neutron-lbaas,gotostack/neutron-lbaas,openstack/networking-odl,openstack/neutron-fwaas,CiscoSystems/networking-odl,FedericoRessi/networking-odl,CiscoSystems/networking-odl,gaolichuang/neutron-fwaas,openstack/networking-odl