Big changes to how `StarModel` fits happen now---fitting now defaults to using MultiNest via PyMultiNest. To take advantage of this change, you must install MultiNest and PyMultiNest. If you don't have these packages, you can follow [these directions](http://astrobetter.com/wiki/MultiNest+Installation+Notes) to install them.
MultiNest does a much better job than `emcee` of exploring the stellar model parameter space when only photometry is being used as observational constraints, because the posterior can be quite multi-modal. As a result, you must use MultiNest if you want a fair fit when you're just using photometry.
The way to fit a `StarModel` now is using the `.fit()` method, which will default to `.fit_multinest()` if MultiNest is available, and will otherwise default back to using `emcee` via `.fit_mcmc()`. Please let me know if you have any troubles with this.
The `starfit` command-line script should work the same as before; again defaulting to MultiNest if available.
In addition, I have finally included unit tests: type `nosetests isochrones` on the command line to run them. If all goes well, everything _should_ be OK.
Another note---- I have also fixed a bug in the dartmouth triangulation file used for interpolation; if you have been using `isochrones` before with the Dartmouth grids, you should get an error now when you try to load them, asking you to delete and re-download the `dartmouth.tri` file. Again, let me know if you have a problem with this.