addding SystemRoot variable to env in job.py

Author: kapilkd13

cwltool/job.py

@@ -297,6 +297,8 @@ def run(self, pull_image=True, rm_container=True,
         env["TMPDIR"] = str(self.tmpdir) if onWindows() else self.tmpdir
         if "PATH" not in env:
             env["PATH"] = str(os.environ["PATH"]) if onWindows() else os.environ["PATH"]
+        if "SYSTEMROOT" not in env and "SYSTEMROOT" in os.environ:
+            env["SYSTEMROOT"] = str(os.environ["SYSTEMROOT"]) if onWindows() else os.environ["SYSTEMROOT"]
 
         stageFiles(self.pathmapper, ignoreWritable=True, symLink=True)
         if self.generatemapper: