robot_state_publisher: 1.9.12-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `robot_state_publisher` to `1.9.12-0`:

- upstream repository: https://github.com/ros/robot_state_publisher.git
- release repository: https://github.com/ros-gbp/robot_state_publisher-release.git
- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.14`
- previous version for package: `1.9.11-0`

## robot_state_publisher

```
* Backporting mimic support
* Contributors: Ioan A Sucan, Konrad Banachowicz
```