Set up continuous integration

In order to properly develop the code and ensure that the work is consistent with previous iterations of pyDARM, we need continuous integration set up early. The list of tasks is as follows:

• Syntax checking (pep8 checks)
• Compare against known results
• Organise list of desired results to compare to
• MCMC comparison tests (KS tests?)
• sanity checks
• model comparisons
• Write the test scripts