octomap_msgs: 0.3.1-2 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `octomap_msgs` to `0.3.1-2`:

- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.9`
- previous version for package: `0.3.1-1`

## octomap_msgs

```
* Removed [binary|full]MsgDataToMap, created only incomplete OctoMap objects
  Replacement: use [binary|full]MsgToMap or msgToMap()
```