Delegate updating of seen_at and read_at to AggregatedActivity
Update aggregated activity's read_at and seen_at attributes using datetime.utcnow
Added Anislav Atanasov to the list of contributors.
Merge pull request #75 from Anislav/feature/update-aggregated-activity-dates

Delegate updating of seen_at and read_at to AggregatedActivity
Update README.md
fix travis badge