Fix for Python 2 on Windows, see #1037.

AUTHORS.txt

@@ -47,5 +47,6 @@ Simon Ruggier (@sruggier)
 Robin Roth (@robinro)
 Malte Plath (@langsamer)
 Anton Zub (@zabulazza)
+Tobias Rzepka (@TobiasRzepka)
 
 Note: (@user) means a github user name.

jedi/evaluate/compiled/subprocess/__init__.py

@@ -138,11 +138,13 @@ class _CompiledSubprocess(object):
             _MAIN_PATH,
             os.path.dirname(os.path.dirname(parso_path))
         )
+        universal_newlines = not is_py3
         return subprocess.Popen(
             args,
             stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
             # stderr=subprocess.PIPE
+            universal_newlines=universal_newlines
         )
 
     def run(self, evaluator, function, args=(), kwargs={}):