Implement get command and model classes
Write Create method
Create ITreeClient
Add Tests for Tree Client
Implement Observable Tree client and refactor names
Create Observable Tests
Add to mono and .net4.5 projects
Add to monotouch and monoandroid projects
Merged Master
Merge branch 'ImplementTreesApi' of https://github.com/pltaylor/octokit.net into pltaylor-ImplementTreesApi
updated the mono csproj files