replaced get_current_week with value 0

[ZachMyers3]

ff-espn-api has the ability to call the current week by passing a parameter of zero.

get_current_week was getting a week earlier than desired, so I've replaced all references of get_current_week() with a zero value.

[dtcarls]

After looking through the new API, all functions that currently use current week can take nothing for week number and is handled to be current week except for power_rankings. I may be cleaner to just get rid of the concept of current week in this bot and let the upstream API handle it.

[ZachMyers3]

There's other features as well, such as built-in power rankings from the API.

I thought the same thing, but figured I'd submit this PR to fix the current issue at hand and go from there.