Merge branch 'develop' into macs2

.gitignore

.travis.yml

bioconda.wdl

biopet.wdl

bwa.wdl

centrifuge.wdl

common.wdl

cutadapt.wdl

fastqc.wdl

flash.wdl

gatk.wdl

htseq.wdl

macs2.wdl

mergecounts.wdl

ncbi.wdl

picard.wdl

samplesheet.wdl

samtools.wdl

seqtk.wdl

spades.wdl