search for fastq files in output folder when using -w

# Pipeline to run UMI-seq analysis from fastq to read count tables.

# Authors: Swati Parekh &  Christoph Ziegenhain

# Contact: sparekh@age.mpg.de or christoph.ziegenhain@ki.se or hellmann@bio.lmu.de

vers=0.0.6d

vers=0.0.6e

function check_opts() {

    value=$1

    name=$2