Cleanup requirements.txt
Cleanup requirements.txt

Because the dashboard is build on Horizon, so remove the
libraries which Horizon already have involved.

Change-Id: I384219ab989b91f2fee0245b9eb24780171f29f3

openstack/senlin-dashboard,openstack/senlin-dashboard,stackforge/senlin-dashboard,openstack/senlin-dashboard,stackforge/senlin-dashboard,stackforge/senlin-dashboard,openstack/senlin-dashboard