Setup Travis-CI (automated test runner)

[jacobbridges]

An automated test runner would help when reviewing future pull requests, as well as testing the project against newer versions of Python.

• [x] Integrate Travis-CI with the project
  • [x] Setup testing against Python 2.7.x, 3.1.x, 3.2.x, 3.3.x, 3.4.x, 3.5.x
  • [x] Setup testing for new pull requests
  • [x] Setup running a new test run against master on every commit