Sybren A. Stüvel
Add a small wrapper around github.com/google/uuid. That way it's clearer which functionality is used by Flamenco, doesn't link most of the code to any specific UUID library, and allows a bit of customisation. The only customisation now is that Flamenco is a bit stricter in the formats it accepts; only the `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx` is accepted. This makes things a little bit stricter, with the advantage that we don't need to do any normalisation of received UUID strings.