removed ambiguous nucleotide checker. no longer needed since snap-dev66
removed ambiguous nucleotide checker. no longer needed since snap-dev66

cboursnell/transrate,cboursnell/transrate,Blahah/transrate,roryk/transrate,Blahah/transrate,roryk/transrate,Blahah/transrate,roryk/transrate,cboursnell/transrate