Use print_function from __future__

Makes these scripts compatible with Python3

Change-Id: I45a96415c4a66f2de87267880885fe63cfcbbe87
diff --git a/contrib/populate-fixture-data.py b/contrib/populate-fixture-data.py
index 99d9a49..93ac34f 100755
--- a/contrib/populate-fixture-data.py
+++ b/contrib/populate-fixture-data.py
@@ -21,6 +21,7 @@
 TODO(hiesel): Add comments
 """
 
+from __future__ import print_function
 import atexit
 import json
 import optparse
@@ -280,7 +281,7 @@
   (options, _) = p.parse_args()
   global BASE_URL
   BASE_URL = BASE_URL % options.port
-  print BASE_URL
+  print(BASE_URL)
 
   set_up()
   gerrit_users = get_random_users(options.user_count)