normalized data for tests working
added helper function for averaging centroid results over multiple runs
centroids for each run now sorted - prep for averaging
find_schools_in_cluster seems to be working... onto tests
sorting bug fixed, but averaging isn't going to work with high clusters as implemented.  Much more variance in clusters found, and sorting them isn't working well.
abandoning K-means for now, actually not best way to get the info we need.  K-means multi-run functionality is WRONG.  It needs to choose the run with the lowest COST, not average the results of multiple runs.