openrtm_common: 3.1.5-8 in 'groovy/release.yaml' [bloom]

Increasing version of package(s) in repository `openrtm_common`:
- previous version: `3.1.5-7`
- new version: `3.1.5-8`
- distro file: `groovy/release.yaml`
- bloom version: `0.4.4`