rocon_multimaster: 0.6.0-0 in 'hydro/release.yaml' [bloom]

Increasing version of package(s) in repository `rocon_multimaster`:
- previous version: `0.5.5-0`
- new version: `0.6.0-0`
- distro file: `hydro/release.yaml`
- bloom version: `0.4.4`