BF: Calling removeColumns mutates the varmap

ukbparse/datatable.py

@@ -261,7 +261,7 @@ class DataTable(object):
         # drop any columns associated
         # with variables that were not
         # listed in the new order.
-        for vid, cols in oldvarmap.items():
+        for vid, cols in list(oldvarmap.items()):
             if vid == 0:
                 continue
             if vid not in vids: