Add default to group_type argument in update_group and create_or_update_group_by_name
Add default to group_type argument in update_group and create_or_update_group_by_name

Doc strings say that group_type defaults to 'internal'. However, when no
value is set to group_type argument, ParamValidationError raised.
The create_or_update_group method adds the default value for the
argument as well.

ianunruh/hvac,ianunruh/hvac