Setup the migration to the new relationships

...ons/0060_prepare_assigned_reviewers_for_data_migration.py

...grations/0061_data_migrate_type_for_assigned_reviewers.py

...pply/funds/migrations/0062_make_reviewer_type_required.py

opentech/apply/funds/models/submissions.py

opentech/apply/funds/models/utils.py

...ech/apply/review/migrations/0017_add_temp_author_field.py

opentech/apply/review/migrations/0018_migrate_author_data.py

...y/review/migrations/0019_replace_existing_author_field.py

opentech/apply/review/models.py