rosh_core: 1.0.3-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `rosh_core` to `1.0.3-0`:

- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.1`
- previous version for package: `1.0.2-0`

## roshlaunch

- No changes

## rosh_core

- No changes

## rosh

```
* make sure shell.py gets put somewhere importable
* Contributors: Dan Lazewatsky
```