Test added to demonstrate addition of subscribers with multi-option (both select one and select many) custom fields.
Test added to demonstrate addition of subscribers with multi-option (both select one and select many) custom fields.

campaignmonitor/createsend-python,campaignmonitor/createsend-python,guilhermetavares/createsend-python,stored/createsend-python,stored/createsend-python,guilhermetavares/createsend-python