Starter code has error in fortmat_datetime function

[MichaelJBigelow]

If the locale is not specified when calling babel.dates.format_datetime(), it throws the following error:
AttributeError: 'NoneType' object has no attribute 'days'

The fix on my Windows 10 machine is the following:
return babel.dates.format_datetime(date, format, locale='en')

[eli-halych]

That fixed it on my Windows 10 machine!

[robinlamb]

I created a pull request that contains this fix, along with some other problems. #117

[SudKul]

Fixed in the #117