Added Test Libraries, Updated Rakefile for Testing

- Fixes #22 - Added Test Libraries, started a sample spec.
- Also added workspace file to include dependencies (OCMock). 
- Added setup info to read me

#### Important to note that you should now launch the project from the workspace it the root of the project directory (OctoKit-Sample.xcworkspace).

#### Also important to note that the setup script now configures the developer for testing. This resolves the dependency with Specta/Expecta. See the Rakefile's setup task to see the process. This needs to be executed again after merging in this commit.