Kleros Integration

[jellegerbrandy]

We are implementing the possibility that in case of disagreement about the severity of a bug report, the unhappy parties can have their dispute arbitrated by Kleros.

Relevant links are the following:

• A google document with specs written by hats: https://docs.google.com/document/d/10q0z1g9lNo9naKqwTE7uEGpC5HuneZ9tklhpfVs9_AY
• A google document with (now outdated) specs written by Kleros, that contains also some more details about the working of Kleros itself: https://docs.google.com/document/d/1JpQoD593_29oi9ihi4n-wQ4kkdghp4x4XdOqg5YbMpE
• A PR with an implementation of a HATConnector.sol contract that integrates HATs v1 with Kleros. This file was later removed from the that is already far along but was abandoned: feat(Connector): add Connector contract #133

[jellegerbrandy]

Current status: the document is updated and lists the changes we need to make in HatVaults. Waiting for feedback from the Kleros people.

[jellegerbrandy]

#133 work is being done here