Track XBlock SDK master for testing
Track XBlock SDK master for testing

This also requires that we add lazy and nose to the test
requirements.

arbrandes/hastexo-xblock,hastexo/hastexo-xblock,arbrandes/hastexo-xblock,arbrandes/hastexo-xblock,hastexo/hastexo-xblock,arbrandes/hastexo-xblock,hastexo/hastexo-xblock,hastexo/hastexo-xblock,arbrandes/hastexo-xblock