Extend notifications module for usage in sync_original_files command

[avrohomgottlieb]

Context

We would like for the sync_original_files command to alert us when files have been modified, created or deleted. At the conclusion of #1040, the notifications module will be created, which will have logic related to sending emails through ses.

Solution or next step

We want to add logic to the notifications module which will allow for the sending of messages over slack to us to alert of changes resulting from the sync_original_files command.