Fix data_interface tests which test ndarray<>list conversion
Fix data_interface tests which test ndarray<>list conversion

Could be a candidate to drop if implementation of read_csv/read_file changes

tomalrussell/smif,willu47/smif,nismod/smif,nismod/smif,willu47/smif,nismod/smif,willu47/smif,tomalrussell/smif,tomalrussell/smif,nismod/smif,tomalrussell/smif,willu47/smif