K Specification of Beacon Chain Phase 0

This release contains

• An updated version of the K model specifying Beacon Chain Phase 0
• Testing scripts and test coverage analysis report
• A technical report documenting the specification and test coverage analysis

Initial implementation of Beacon Chain phase 0 spec + hashing

Cleanup and fixes. Addressing remaining TODOs (#45)

* fixed setHistoricalRootAccumulator

* cleaned up comments

* deteled 2 addressed todo-s

* beacon-chain: fixed the implementation of setHistoricalRootAccumulator()