Simple exercise using python and basemap to visualize spatial data

This is a simple exercise that partially mimics the workflow of the introductory numpy lesson to introduce and motivate audiences that work with spatial data. Taking the latitude and longitude values of all of the bootcamps in the swcarpentry/site repo (script to scrape the data and create the .csv file is in `python/util/get_bootcamp_coords.py`), the notebook walks through loading the data and building a simple visualization.

This lesson was created as part of the instructor training course.

@gvwilson - Comments would be appreciated. I'm happy to do more work to make this useable in a real bootcamp, although it was largely designed as an exercise for the training.