Update licenses

[danielpeintner]

With kotlin-wot we need to add "Apache-2.0" and "CC-BY-4.0" also...

See https://thingweb.io/get-involved/#licenses

[egekorkan]

Oops :D

Should we simply say "Look in the repo you are contributing to"?

[danielpeintner]

Yes, either we list them all or say we use open source licenses, and please check them out based on the project.