Requirements tags for some samtools tools

tools/samtools/bam_to_sam.xml

@@ -1,4 +1,7 @@
 <tool id="bam_to_sam" name="BAM-to-SAM" version="1.0.0">
+  <requirements>
+    <requirement type="package">samtools</requirement>
+  </requirements>
   <description>converts BAM format to SAM format</description>
   <command interpreter="python">bam_to_sam.py --input1=$input1 --output1=$output1</command>
   <inputs>

tools/samtools/pileup_interval.xml

@@ -1,5 +1,8 @@
 <tool id="pileup_interval" name="Pileup-to-Interval" version="1.0.0">
   <description>condenses pileup format into ranges of bases</description>
+  <requirements>
+    <requirement type="package">samtools</requirement>
+  </requirements>
   <command interpreter="python">
     pileup_interval.py 
       --input=$input 

tools/samtools/sam_merge.xml

@@ -1,5 +1,8 @@
 <tool id="sam_merge" name="Merge BAM Files" version="1.1.0">
   <description>merges BAM files together</description>
+  <requirements>
+    <requirement type="package">samtools</requirement>
+  </requirements>
   <command interpreter="python">
    sam_merge.py 
       $input1

tools/samtools/sam_pileup.xml

@@ -1,5 +1,8 @@
 <tool id="sam_pileup" name="Generate pileup" version="1.1.0">
   <description>from BAM dataset</description>
+  <requirements>
+    <requirement type="package">samtools</requirement>
+  </requirements>
   <command interpreter="python">
     sam_pileup.py
         --input1=$input1

tools/samtools/sam_to_bam.xml

@@ -1,5 +1,8 @@
 <tool id="sam_to_bam" name="SAM-to-BAM" version="1.1.0">
   <description>converts SAM format to BAM format</description>
+  <requirements>
+    <requirement type="package">samtools</requirement>
+  </requirements>
   <command interpreter="python">
 sam_to_bam.py --input1=$source.input1 --dbkey=${input1.metadata.dbkey} 
 #if $source.index_source == "history":