Updated Travis build to include Volume 3.
Also fixed bug where no test script was run.
Merge pull request #641 from insertinterestingnamehere/travis

Updated Travis build to include Volume 3.
Modified source for Travis build widget in README.rst.
Merge pull request #642 from insertinterestingnamehere/travis

Modified source for Travis build widget in README.rst.
Merge branch 'develop' of https://github.com/byuimpact/numerical_computing into develop