grasping_msgs: 0.3.1-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `grasping_msgs` to `0.3.1-0`:

- upstream repository: git@github.com:mikeferguson/grasping_msgs.git
- release repository: https://github.com/mikeferguson/grasping_msgs-gbp.git
- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.12`
- previous version for package: `0.3.0-0`

## grasping_msgs

```
* update email
* update description in package.xml
* Contributors: Michael Ferguson
```