Fix token_flush command
Fix token_flush command

keystone-manage is using token_flush and not token-flush. Also
stdout and stderr redirection has been fixed.

Change-Id: Ia35574be51c415c49f80276b510caca1ab0b994f

openstack/packstack,xbezdick/packstack,fr34k8/packstack,palmer159/openstack-test,larsks/packstack,palmer159/openstack-test,mahak/packstack,openstack/packstack,imcsk8/packstack,stackforge/packstack,stackforge/packstack,larsks/packstack,fr34k8/packstack,imcsk8/packstack,fr34k8/packstack,openstack/packstack,palmer159/openstack-test,xbezdick/packstack,mahak/packstack,larsks/packstack,mahak/packstack,stackforge/packstack,imcsk8/packstack,xbezdick/packstack