Added upper/lower case support for S3 prefix
Added upper/lower case support for S3 prefix

mick-d/nipype,mick-d/nipype,sgiavasis/nipype,carolFrohlich/nipype,FCP-INDI/nipype,carolFrohlich/nipype,sgiavasis/nipype,mick-d/nipype,FCP-INDI/nipype,FCP-INDI/nipype,FCP-INDI/nipype,sgiavasis/nipype,carolFrohlich/nipype,carolFrohlich/nipype,sgiavasis/nipype,mick-d/nipype