nf_module: sratoolkit add DSL2

src/nf_modules/sratoolkit/main.nf

+version = "2.8.2"
+container_url = "lbmc/sratoolkit:${version}"
+
+process index_fasta {
+  container = "${container_url}"
+  label "big_mem_mono_cpus"
+  tag "$sra"
+
+  input:
+    val sra
+
+  output:
+    tuple val(sra), path("*.fastq"), emit: fastq
+
+  script:
+"""
+fastq-dump --split-files --gzip ${sra}
+if [ -f ${sra}_1.fastq ]
+then
+  mv ${sra}_1.fastq ${sra}_R1.fastq
+fi
+if [ -f ${sra}_2.fastq ]
+then
+  mv ${sra}_2.fastq ${sra}_R2.fastq
+fi
+"""
+}