New index columns are not deterministic #24
Description
New index column names are not deterministic as they are created by joining together items in an unsorted list in make_indexes() in normalize.py. This should be updated so that new index names are consistent from run to run. This can be accomplished by sorting the list prior to joining into a new column name.
After making this update, the tests implemented in PR #12 should also be reviewed and updated if needed.