cast return value to str in getoutput

IPython/utils/_process_win32.py

@@ -155,7 +155,7 b' def getoutput(cmd):'
 
     if out is None:
         out = ''
-    return out
+    return py3compat.bytes_to_str(out)
 
 try:
     CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW