Remove tox-cover from nodepool
There's no need to have this defined in project-config. It's perfectly
reasonable to have this in-tree.
templates:
- system-required
- publish-to-pypi
- check:
- jobs:
- - tox-cover
- post:
- jobs:
- - tox-cover
- project:
name: openstack-infra/nose-html-output
