Add custom default times based on weekday

[HPApples]

Currently Default operation time is defined in commandListener.py:

operationbot/commandListener.py

Line 36 in b1fec15

return date.replace(hour=18, minute=30)

If we could make this take values from the CONFIG file and re define the end of the converter to something like a IF ELIF based on date.weekday() we could specify the times for each day.

[HPApples]

In addition timezone is hard coded on line 212 of event.py

title = "{} ({})".format( self.title, self.date.strftime("%a %Y-%m-%d - %H:%M CET"))

This would also be useful to have a global config variable to reference (especially when timezone changes to CEST/CET GMT/BST)

[Gehock]

Time zone should be fairly simple to implement, made a separate issue about it: #50.

Weekday time could be implemented by configuring the default time in config.py and having separate a dict with day's name as key and time as value.

One possible implementation could be something like this:

config.py:

DEFAULT_TIME = datetime(hour=18, minute=30)
WEEK_TIMES = {
  5: datetime(hour=18, minute=45),  # friday
  6: datetime(hour=17, minute=0),  # saturday
}

event creation:

event_time = cfg.WEEK_TIMES.get(date.isoweekday(), cfg.DEFAULT_TIME)

[HPApples]

I think that is the neatest method we will get.

[Gehock]

A version of this was implemented in HPApples@d58131e, could cherry-pick at some point