use django tempfile implementation to provide windows support

pipeline/compressors/csstidy/__init__.py

-import os
-import tempfile
+from django.core.files import temp as tempfile
 
 from pipeline.conf import settings
 from pipeline.compressors import SubProcessCompressor
@@ -7,18 +6,15 @@ from pipeline.compressors import SubProcessCompressor
 
 class CSSTidyCompressor(SubProcessCompressor):
     def compress_css(self, css):
-        out_file, out_filename = tempfile.mkstemp()
-        out_file = os.fdopen(out_file, 'rb')
+        output_file = tempfile.NamedTemporaryFile(suffix='.pipeline')
 
         command = '%s - %s %s' % (
             settings.PIPELINE_CSSTIDY_BINARY,
             settings.PIPELINE_CSSTIDY_ARGUMENTS,
-            out_filename
+            output_file.name
         )
         self.execute_command(command, css)
 
-        filtered_css = out_file.read()
-        out_file.close()
-        os.remove(out_filename)
-
+        filtered_css = output_file.read()
+        output_file.close()
         return filtered_css