Remove sample name from config

Snake.config.json

 {
-    "sample"        : "D2Rfb",
     "chromosomes"   : ["chr1","chr2","chr3","chr4","chr5","chr6","chr7","chr8","chr9","chr10","chr11","chr12","chr13","chr14","chr15","chr16","chr17","chr18","chr19","chr20","chr21","chr22"],
 
     "reference"     : "/g/korbel/shared/datasets/refgenomes/human/hg19_chr1_22XYM.fa",
@@ -10,7 +9,7 @@
     "samtools"      : "samtools",
     "bcftools"      : "bcftools",
 
-    "snv_calls"     : "",
+    "snv_calls"     : {},
 
     "exclude_file"  : "/g/korbel/meiers/tools/mosaicatcher/mosaicatcher/data/exclude/hg19.exclude",
     "variable_bins" : {