don't remove the file under cygwin.

Thanks to @pombredanne for the report. fix #407

gunicorn/workers/workertmp.py

@@ -4,10 +4,16 @@
 # See the NOTICE for more information.
 
 import os
+import platform
 import tempfile
 
 from gunicorn import util
 
+PLATFORM = platform.system()
+if PLATFORM.startswith('CYGWIN'):
+    IS_CYGWIN = True
+else:
+    IS_CYGWIN = False
 
 class WorkerTmp(object):
 
@@ -21,7 +27,8 @@ class WorkerTmp(object):
 
         # unlink the file so we don't leak tempory files
         try:
-            util.unlink(name)
+            if not IS_CYGWIN:
+                util.unlink(name)
             self._tmp = os.fdopen(fd, 'w+b', 1)
         except:
             os.close(fd)