fix AttributeError: module 'collections' has no attribute 'abc'

Solutions/2_5/readrides.py

@@ -1,6 +1,7 @@
 # readrides.py
 
 import csv
+import collections.abc
 
 def read_rides_as_tuples(filename):
     '''

Solutions/2_6/colreader.py

@@ -1,6 +1,7 @@
 # colreader.py
 
 import collections
+import collections.abc
 import csv
 
 class DataCollection(collections.abc.Sequence):