urdf_tutorial: 0.2.3-0 in 'indigo/distribution.yaml' [bloom]

Increasing version of package(s) in repository `urdf_tutorial` to `0.2.3-0`:

- distro file: `indigo/distribution.yaml`
- bloom version: `0.5.7`
- previous version for package: `null`

## urdf_tutorial

```
* Merge pull request #7 <https://github.com/ros/urdf_tutorial/issues/7> from gavanderhoorn/issue6_source_vs_devel_vs_install
  Fix issue #6 <https://github.com/ros/urdf_tutorial/issues/6>: No robot model when using display.launch (again)
* Setup new directory structure and move files around.
* Contributors: Ioan A Sucan, gavanderhoorn
```