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 188.8.131.52b3 is required at least.
Also drops unnecessary Django dependencies. There is no need to
install Django explicitly as it is a horizon dependency.
The lower bound of oslo.log is added to pass requirements-check job.
The new lower bound is picked up from lower-constraints.txt.