Include site-packages on travis and skip tests otherwise

.travis.yml

@@ -1,5 +1,6 @@
 language: python
-python: 2.7
+virtualenv:
+    system_site_packages: true
 
 branches:
     only:

test/test_replaygain.py

@@ -27,6 +27,13 @@ from beets import plugins
 from beets.library import Item, Album
 from beets.mediafile import MediaFile
 
+try:
+    import gi
+    gi.require_version('Gst', '1.0')
+    GST_AVAILABLE = True
+except ImportError, ValueError:
+    GST_AVAILABLE = False
+
 
 class ReplayGainCliTestBase(object):
 
@@ -117,8 +124,6 @@ class ReplayGainCliTestBase(object):
         self.assertEqual(item.rg_track_gain, 0.0)
         self.assertEqual(item.rg_track_peak, peak)
 
-
-
     def test_cli_saves_album_gain_to_file(self):
         for item in self.lib.items():
             mediafile = MediaFile(item.path)
@@ -142,6 +147,7 @@ class ReplayGainCliTestBase(object):
         self.assertNotEqual(max(peaks), 0.0)
 
 
+@unittest.skipIf(not GST_AVAILABLE, 'gstreamer cannot be found')
 class ReplayGainGstCliTest(ReplayGainCliTestBase, unittest.TestCase):
     backend = u'gstreamer'
 

tox.ini

@@ -14,6 +14,7 @@ deps =
     responses
 commands =
     nosetests
+sitepackages = True
 
 [testenv:py26]
 deps =