updated prediction transcript tests to check new display_label attribute
updated prediction transcript tests to check new display_label attribute

at7/ensembl,james-monkeyshines/ensembl,james-monkeyshines/ensembl,Ensembl/ensembl,at7/ensembl,Ensembl/ensembl,mjg17/ensembl,muffato/ensembl,danstaines/ensembl,willmclaren/ensembl,mjg17/ensembl,danstaines/ensembl,muffato/ensembl,muffato/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl,danstaines/ensembl,at7/ensembl,mjg17/ensembl,at7/ensembl,james-monkeyshines/ensembl,willmclaren/ensembl,Ensembl/ensembl,muffato/ensembl,mjg17/ensembl