Add integer to database array

# Update Business' supported_causes list and Cause's list of supporters
def update_supporters
	@transaction = Transaction.find(self.id)
	@type = @transaction.trans_type
	@status = @transaction.status
	if @type == 'pledge' && @status == 'complete' then
		@business_id = @transaction.from_user_id
		@cause_id = @transaction.to_user_id
		b = User.find(@business_id)
		b.supported_causes += Array(@cause_id)
		b.save!
		c = User.find(@cause_id)
		c.supporters += Array(@business_id)
		c.save!
	end
end