Adds support for AWS Session Profile with a new setting.
This is a minor bump due to the new setting, it also changes the way the
connection is initialized, see [here](https://github.com/django-ses/django-ses/pull/323/files#diff-0cbba929f061bb8c1faa375bac96beeb00879395919333f2c0a0791e8a9265a7R109).
Pulls:
- https://github.com/django-ses/django-ses/pull/323
Issues:
- https://github.com/django-ses/django-ses/issues/322