added some tests for creation of slices sans db and coord system
added some tests for creation of slices sans db and coord system

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