pr2_plugs: 1.0.21-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `pr2_plugs` to `1.0.21-0`:

- upstream repository: https://github.com/PR2/pr2_plugs.git
- release repository: https://github.com/TheDash/pr2_plugs-release.git
- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.12`
- previous version for package: `1.0.19-0`

## checkerboard_pose_estimation

```
* Added install dependency from checkerboard_pose to find ros_detect.h
* Contributors: TheDash
```

## outlet_pose_estimation

- No changes

## pr2_image_snapshot_recorder

- No changes

## pr2_plugs

- No changes

## pr2_plugs_actions

```
* Added install dependency from checkerboard_pose to find ros_detect.h
* Contributors: TheDash
```

## pr2_plugs_common

```
* Added install dependency from checkerboard_pose to find ros_detect.h
* Contributors: TheDash
```

## pr2_plugs_msgs

- No changes

## stereo_wall_detection

- No changes

## visual_pose_estimation

- No changes