Horizon test setting no longer depends on nose and related stuffs.
This commit cleans up nose related dependencies.
The change was made in horizon Rocky-3,
so horizon 14.0.0.0b3 is required at least.
Also drops unnecessary Django dependencies. There is no need to
install Django explicitly as it is a horizon dependency.
Babel is dropped from the same reason.
Change-Id: I8bc25f8530f25cdb0519bd611812379ef183fca1
1676384c03