[docs] time.strftime

[Fülemüle Vera]

Hi,

I have noticed a mistake in the 2.7.8 Documentation about time.strftime 
return types.
According to the documentation the time.strftime("%m") and 
time.strftime("%d") are "zero-padded decimal number" but their return 
types are string.
URL: 
https://docs.python.org/2/library/datetime.html#strftime-strptime-behavior

Best regards,
Vera