Watched Client and Unit Tests
Reactive Watched Client
Fixed Projects
Merge branch 'master' into watched-client

Conflicts:
	Octokit.Reactive/Clients/IObservableActivitiesClient.cs
	Octokit.Reactive/Clients/ObservableActivitiesClient.cs
Merge pull request #350 from nigel-sampson/watched-client

Implement Activity Watching API