The hour never gets updated within runtime
The hour never gets updated within runtime

The current_hour [`datetime`] was never getting updated during runtime and it was just being set once. I've fixed that issue by not setting the hour to a variable.
This PR *also* has a few small PEP8 updates and cleaned up the `datetime` math by using `timedelta` too. :)

TeachersPayTeachers/slackbot-workout