Updated Sanger quality range

From the wiki

>Sanger format can encode a Phred quality score from 0 to 93 using ASCII 33 to 126 (although in raw read data the Phred quality score rarely exceeds 60


60 + 33 = 93. Using 73 means some high quality Sanger encoded data will not be determined (I had this issue having data with quality scores above 40).
Merge pull request #8 from simonohanlon101/patch-1

Updated Sanger quality range