added check_variant_size code
added check_variant_size code

dbolser/ensembl-variation,Ensembl/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,dbolser/ensembl-variation,willmclaren/ensembl-variation,dbolser-ebi/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,dbolser-ebi/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation,dbolser-ebi/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation