Stable Toychain release

This release snapshots the stable functionality of the Toychain project:

• Implementation of block forests;
• Implementation of the replicated state machines;
• The proof of eventual consistency;
• Extraction and trusted shim.

Details of the system are described in George Pîrlea's MEng thesis.

Toychain v0.2

Version in George Pîrlea's Master's thesis at UCL (29 April 2019).

Toychain v0.1

A version accepted at CPP 2018.