image_encoding_speed_test.py broken with python 2

[springmeyer]

Looks like this broke in d2a2afa.

This seems to work in python 2:

diff --git a/test/python_tests/image_encoding_speed_test.py b/test/python_tests/image_encoding_speed_test.py
index 58f0785..251658f 100644
--- a/test/python_tests/image_encoding_speed_test.py
+++ b/test/python_tests/image_encoding_speed_test.py
@@ -6,7 +6,7 @@ from timeit import Timer, time

 import mapnik

-from .utilities import execution_path, run_all
+from utilities import execution_path, run_all


 def setup():
@@ -113,7 +113,7 @@ def do_encoding():
             t = Timer(aerial_24)
             run(aerial_24, aerial_24_im, c, t)

-    for key, value in sorted(sortable.iteritems(), key=lambda k, v: (v, k)):
+    for key, value in sorted(sortable.iteritems(), key=lambda (k, v): (v, k)):
         s = results[key]
         min_ = str(s[0])[:6]
         avg = str(s[1])[:6]