Since lijun's education discount expires, we can no longer use travis-ci.com for CI purposes. There is virtually no difference between travis-ci.org and travis-ci.com for public repositories. Thus, I switched all travis-ci related settings to travis-ci.org.
Fix #10
Since lijun's education discount expires, we can no longer use travis-ci.com for CI purposes. There is virtually no difference between travis-ci.org and travis-ci.com for public repositories. Thus, I switched all travis-ci related settings to travis-ci.org.