Decide a License for all the softaware in GobstonesWeb2

[fidel-ml]

We need to decide a License that suits our needs.

Currently we are using MIT, but there is a proposal to migrate to Afero GPL3.0.

To discuss this issue, we have a thread on Gobstones Community, dev-core (if you don't see it, your role may not be the right one -- ask admins).

[fidel-ml]

After deciding it, we need to update gobstones-guidelines and gobstones-scripts.