move jenkins_slave dockerfiles under tools/dockerfile
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 767b801..7482824 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -576,9 +576,9 @@
 def _get_dockerfile_dir(arch):
   """Returns dockerfile to use"""
   if arch == 'default' or arch == 'x64':
-    return 'tools/jenkins/grpc_jenkins_slave'
+    return 'tools/dockerfile/grpc_jenkins_slave_x64'
   elif arch == 'x86':
-    return 'tools/jenkins/grpc_jenkins_slave_32bits'
+    return 'tools/dockerfile/grpc_jenkins_slave_x86'
   else:
     print 'Architecture %s not supported with current settings.' % arch
     sys.exit(1)