Add actor coordination test
Merge pull request #125 from edrevo/add-actor-coordination-test

Add actor coordination test
Implement connect() in DefaultCoinffeineNetwork
Merge pull request #127 from sortega/feature/network-connect

Implement connect() in DefaultCoinffeineNetwork
Introduce versioning in the protocol

Use the simplest criterium when parsing messages: rejecting messages with any version
other than the current one.
Merge pull request #129 from sortega/feature/versioning

Introduce versioning in the protocol
Add mock payment processor for testing
Refactor the exchange class to make it consistent with the Handshake class
Implement DefaultExchange