fixed tests so they run properly under tox, and added verbosity to test output

test_xvfb.py

@@ -4,18 +4,13 @@
 from xvfbwrapper import Xvfb
 
 import os
-import sys
 import unittest
 
 
 class TestXvfb(unittest.TestCase):
 
     def setUp(self):
-        sys.stdout = sys.__stdout__
-        self.addCleanup(self.restore_stdout)
-
-    def restore_stdout(self):
-        sys.stdout = sys.__stdout__
+        os.environ['DISPLAY'] = ':0'
 
     def test_start(self):
         xvfb = Xvfb()

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = flake8, py27, py32, py33
+envlist = flake8, py27, py32, py33, py34, pypy
 
 [flake8]
 exclude = .tox, build
@@ -14,7 +14,7 @@ deps =
     nose
 commands =
     {envpython} setup.py install
-    nosetests
+    nosetests -v
 
 [testenv:flake8]
 deps =