Update AUTHORS, directly link to Github contributor list
Update AUTHORS, directly link to Github contributor list

Adys/django-push-notifications,jamaalscarlett/django-push-notifications,cristiano2lopes/django-push-notifications,jleclanche/django-push-notifications,lukeburden/django-push-notifications,matthewh/django-push-notifications,rsalmaso/django-push-notifications,shigmas/django-push-notifications