Update rewards (first -> second -> third -> (disabled))

[strager]

The bot should automatically rename and update rewards.

If the reward is the 'first' reward, it should be renamed to the 'second' reward. In addition, the per-stream redemption limit should be raised so that someone else can claim the reward.

After the final reward is collected, it should reset back to the state of the first reward; its name and redemption limit should be reset.

The streamer should be able to configure (#17) the name of the rewards, how many rewards there are, and the points allocated for each reward.

[strager]

This realistically depends on #17.

[strager]

if first:

• name -> second
• redemptions per stream -> 2

if second:

• name -> third
• redemptions per stream -> 3

if third:

• name -> first
• redemptions per stream -> 1

[strager]

@mate-amargo implemented this, but I'll need to test it in production during a live stream.