Version control of the parts

[qgeissmann]

We must have a tag/naming system to identify each arena. If we keep the same repo structure, we can automatically generate a table.

[qgeissmann]

I suggest using a YAML file as README.md. eg https://github.com/PolygonalTree/ethoscope_hardware/tree/master/arenas/master%20arena
This way we can parse description very effectively.
Please, @PolygonalTree amend the master with other fields so we can mimic that for other objects.

[pepelisu]

We will use the commit id as version control, as we saw yesterday that it is easy to recover old versions.