setup.py

@rsignell-usgs To answer your question on packaging:

I usually follow [these](http://python-packaging-user-guide.readthedocs.org/en/latest/tutorial.html) instructions.  Basically all you need to turn `ncml` into a package is a `setup.py` file.  This PR implements an example of that.

With the PR you can:
- `python setup.py sdist` creates a tarball.  You can install the tarball with `pip` or `conda`.
- `python setup.py register`  registers at PyPI.  Do that to get the `ncml` name before some else does!
- `python setup.py upload` sends to PyPI.  That way others can: `pip install ncml`
- and of course `python setup.py install` to install it locally.

I used a `FILL_ME` variable as a place holder to the missing metadata in your package.