library_helpers: Send SIGTERM as root

refs #3012

Change-Id: Ic388a201d9e83a6540d737de803e837ecfb056fb
diff --git a/library_helpers/process_manager.py b/library_helpers/process_manager.py
index ac53b0f..db686f6 100644
--- a/library_helpers/process_manager.py
+++ b/library_helpers/process_manager.py
@@ -71,7 +71,7 @@
 
     def killProcess(self, processKey):
         if processKey not in self.results and processKey in self.subprocesses:
-            self.subprocesses[processKey].terminate()
+            subprocess.call(['sudo', 'kill', str(self.subprocesses[processKey].pid)])
 
     def hasProcessCompleted(self, processKey):
         if processKey in self.results: