Skip gstreamer tests on windows

tests/backends/gstreamer_test.py

@@ -1,5 +1,6 @@
 import unittest
 import os
+import sys
 import urllib
 
 from mopidy import settings
@@ -13,6 +14,9 @@ from tests import SkipTest, data_folder
 song = data_folder('song%s.wav')
 generate_song = lambda i: 'file://' + urllib.pathname2url(song % i)
 
+if sys.platform not in ['linux2', 'darwin']:
+    raise SkipTest
+
 # FIXME can be switched to generic test
 class GStreamerCurrentPlaylistHandlerTest(BaseCurrentPlaylistControllerTest, unittest.TestCase):
     tracks = [Track(uri=generate_song(i), id=i, length=4464) for i in range(1, 4)]