Scheduled Locks

[Kav-K]

We want to be able to lock a channel for a specified amount of time, with the argument in AdBhCm format.

Amend the existing !lock command to take in an argument, if no argument is provided consider it as a permanent lock. Store the lock time in redis and use an existing task or a new task to poll the locked channels and determine when to unlock them.

The bot should send two messages, one message when it's locked that says how much time is remaining in the lock, and another message when the channel unlocks.