nice_time has incorrect param type annotation

[NeonDaniel]

Describe the bug
nice_time indicates an argument type of datetime, but it should be datetime.datetime

lingua-franca/lingua_franca/format.py

Line 273 in eb6d677

dt (datetime): date to format (assumes already in local timezone)

To Reproduce
Steps to reproduce the behavior:

from mycroft.util.format import nice_time
nice_time(datetime.now(tz), lang)
# editor will warn: Expected type 'datetime.pyi', got 'datetime' instead 

Expected behavior
nice_time method should expect a datetime type, not datetime.pyi

Environment (please complete the following information):

• Device type: Desktop
• OS: Ubuntu 20.04
• Mycroft-core version: N/A
• Other versions: lingua-franca-0.4.2