Setup Mithril Network fake cryptographic artifacts

[jpraynaud]

We need to prepare fake data and artifacts that will be used by the nodes of the Mithril Network with the following assertions:

• The real Mithril cryptographic library is used
• Stake distribution is static and fake
• Signer keys are static

1. Setup

• Add features to the protocol demo tool to export:
  • private/public keys for signers
  • single signatures
  • multi signature
• Create fake signer data (party_id, private_key, public_key, stake) by using the protocol demo tool
• Determine loose protocol parameters to use with a limited pool of signers
• Add these data to the aggregator fake data module (signers parameters)
• Compute the beacon parameters using Unix time, to make them dynamic