put default tmpdir as $TMPDIR to solve potential issues with picard and spp

config/config.yaml

@@ -36,7 +36,7 @@ input_extension: '.fastq.gz'
 # directory where you want to store results
 analysis_dir: /path/to/directory/analysis
 # tmpdir: write tempory file on this directory (default /tmp/, but could be "/local/scratch/")
-tmpdir: "/tmp/"
+tmpdir: $TMPDIR
 
 #===============================================================================
 # Design information. These informations will be used during the