added subsampling step to genebody_coverage
added subsampling step to genebody_coverage

ewels/NGI-RNAseq,SciLifeLab/NGI-RNAseq,Hammarn/NGI-RNAseq,Hammarn/NGI-RNAseq,ewels/NGI-RNAseq,SciLifeLab/NGI-RNAseq,ewels/NGI-RNAseq,SciLifeLab/NGI-RNAseq,SciLifeLab/NGI-RNAseq,ewels/NGI-RNAseq,Hammarn/NGI-RNAseq,Hammarn/NGI-RNAseq,Hammarn/NGI-RNAseq,SciLifeLab/NGI-RNAseq,ewels/NGI-RNAseq