BUG: Clubs should not be able to use more than their points allowed

[dompatmore]

When:

A secretary redeems more points than they have available, which would leave them in the negative

Then:

They receive a confirmation message

Expected:

They should not be able to redeem more points than available; this should be done within the UI. 
The redeemed points should be correctly deducted from the club's total.