Add tests for fetch_all_somatic_by_Slice_size_range and fetch_all_by_Slice_size_range
Add tests for fetch_all_somatic_by_Slice_size_range and
fetch_all_by_Slice_size_range

Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation