fixed header unit tests for CRAM files
fixed header unit tests for CRAM files

bioinformed/pysam,kyleabeauchamp/pysam,daler/pysam,dannon/pysam,daler/pysam,TyberiusPrime/pysam,nlhepler/pysam,brendanofallon/pysam,TyberiusPrime/pysam,pysam-developers/pysam,daler/pysam,nlhepler/pysam,pysam-developers/pysam,dannon/pysam,daler/pysam,kyleabeauchamp/pysam,dannon/pysam,kyleabeauchamp/pysam,dannon/pysam,bioinformed/pysam,pysam-developers/pysam,bioinformed/pysam,pysam-developers/pysam,bioinformed/pysam,mattions/pysam,mattions/pysam,brendanofallon/pysam,nlhepler/pysam,nlhepler/pysam,carolinux/pysam,brendanofallon/pysam,daler/pysam,TyberiusPrime/pysam,dannon/pysam,carolinux/pysam,mattions/pysam,mattions/pysam,mattions/pysam,brendanofallon/pysam,brendanofallon/pysam,TyberiusPrime/pysam,kyleabeauchamp/pysam,carolinux/pysam,kyleabeauchamp/pysam,TyberiusPrime/pysam,bioinformed/pysam,carolinux/pysam,nlhepler/pysam,carolinux/pysam