DADA script for quality plots doesn't work with all sequence file extensions

[cjfields]

Minor error that needs to be addressed, but this line in the DadaQC.R template script doesn't work if the file extensions don't include fastq:

TADA/templates/DadaQC.R

Line 5 in f5e793e

fns <- list.files(pattern="fastq", full.names=TRUE)

This should be made more flexible, or only run one file at a time (the current version is meant to run with multiple FASTQ files if they are given, but the pipeline runs these one at a time).