Bump pbr from 5.6.0 to 5.7.0
Bump pbr from 5.6.0 to 5.7.0

Bumps [pbr](https://docs.openstack.org/pbr/latest/) from 5.6.0 to 5.7.0.

---
updated-dependencies:
- dependency-name: pbr
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
dpursehouse/pygerrit2