Relative imports don't work because the test dir isn't a proper python module.

--- xcffib-0.4.2/test/test_connection.py
+++ xcffib-0.4.2/test/test_connection.py
@@ -20,7 +20,7 @@
 
 from xcffib import ffi
 from xcffib.testing import XvfbTest
-from .testing import XcffibTest
+from testing import XcffibTest
 
 from nose.tools import raises
 from nose import SkipTest
--- xcffib-0.4.2/test/test_fakeinput.py
+++ xcffib-0.4.2/test/test_fakeinput.py
@@ -2,7 +2,7 @@
 import xcffib.xproto
 import xcffib.xtest
 
-from .testing import XcffibTest
+from testing import XcffibTest
 
 class TestConnection(XcffibTest):
     def test_fakeinput(self):
--- xcffib-0.4.2/test/test_python_code.py
+++ xcffib-0.4.2/test/test_python_code.py
@@ -18,7 +18,7 @@
 import struct
 from xcffib.xproto import EventMask
 
-from .testing import XcffibTest
+from testing import XcffibTest
 
 class TestPythonCode(XcffibTest):