get rid of warnings in test.projection.iter

sample warnings (to be expected given test):
2: In sgp.iter[["sgp.content.areas"]] ==
tmp.content_area.projection.sequence :
  longer object length is not a multiple of shorter object length
3: In sgp.iter[["sgp.grade.sequences"]] ==
tmp.grade.projection.sequence :
  longer object length is not a multiple of shorter object length