Remove openstack-pipeline-lock
Remove openstack-pipeline-lock

- use serial_groups instead
- also set serial for all jobs

Signed-off-by: Felix Riegger <9c2aa7530239a330bbac6ac4f56e0946781dfd29@sap.com>

cloudfoundry-incubator/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release