Use collections.abc instead of collections for better compatibility with Python3
Use collections.abc instead of collections for better compatibility with Python3

Change-Id: I637524bcce67f1477dc68494d388279997861ac4
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/3899270
Auto-Submit: Andrey Logvin <d1a9cba877864cffb2bba2f18040e3a770e73eed@google.com>
Reviewed-by: Mikhail Khokhlov <26a5474f563e73cb4d4e9a12e954c50f60aae4c8@google.com>
Commit-Queue: Andrey Logvin <d1a9cba877864cffb2bba2f18040e3a770e73eed@google.com>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult