Work around bug in capturing output on windows.

On Windows with Python >= 3.6.0, the console handling seems to have
changed and this seems to break our capturing the file descriptor to
suppress the compilation messages on the console.  pytest has a fix
here: pytest-dev/pytest#2462 but we essentially
do not do any capturing on windows for these Python versions as this fix
doesn't seem to help us here.  Hopefully this will be resolved in
Python itself at some point but for now this error was breaking any
compilation using compyle on Windows.

Author: prabhuramachandran

compyle/capture_stream.py

@@ -34,13 +34,17 @@ def __init__(self, stream=sys.stderr):
         self._cached_output = None
 
     def __enter__(self):
+        if sys.platform.startswith('win32') and sys.version_info[:2] > (3, 5):
+            return self
         self.orig_stream = os.dup(self.fileno)
         self.tmp_path = mktemp()
         self.tmp_stream = open(self.tmp_path, 'w+')
         os.dup2(self.tmp_stream.fileno(), self.fileno)
         return self
 
     def __exit__(self, type, value, tb):
+        if sys.platform.startswith('win32') and sys.version_info[:2] > (3, 5):
+            return
         if self.orig_stream is not None:
             os.dup2(self.orig_stream, self.fileno)
         if self.tmp_stream is not None:
@@ -66,19 +70,23 @@ def get_output(self):
             self._cache_output()
         return self._cached_output
 
+
 class CaptureMultipleStreams(object):
     """This lets one capture multiple streams together.
     """
     def __init__(self, streams=None):
         streams = (sys.stdout, sys.stderr) if streams is None else streams
         self.streams = streams
         self.captures = [CaptureStream(x) for x in streams]
+
     def __enter__(self):
         for capture in self.captures:
             capture.__enter__()
         return self
+
     def __exit__(self, type, value, tb):
         for capture in self.captures:
             capture.__exit__(type, value, tb)
+
     def get_output(self):
         return tuple(x.get_output() for x in self.captures)