Added SuperCollider and Graphviz to Travis-CI build process.
Added SuperCollider and Graphviz to Travis-CI build process.

josiah-wolf-oberholtzer/supriya,andrewyoung1991/supriya,andrewyoung1991/supriya,Pulgama/supriya,andrewyoung1991/supriya,Pulgama/supriya,Pulgama/supriya,Pulgama/supriya