octomap_msgs: 0.3.1-1 in 'hydro/release.yaml' [bloom]

Increasing version of package(s) in repository `octomap_msgs`:
- previous version: `0.3.0-0`
- new version: `0.3.1-1`
- distro file: `hydro/release.yaml`
- bloom version: `0.4.2`