Fix SimpleBogus gateway.

SimpleBogus gateway was breaking when trying to process credit card payments. Since the SimpleBogus gateway does not have payment profiles enabled, the following code runs when you process a payment:


```ruby
# Standard ActiveMerchant capture usage
response = payment_method.capture(money.money.cents,
                                  response_code,
                                  gateway_options)
```

https://github.com/spree/spree/blob/master/core/app/models/spree/payment/processing.rb#L46-L50

SimpleBogusGateway inherits its process method from BogusGateway:
```ruby
def capture(authorization, credit_card, gateway_options)
  if authorization.response_code == '12345'
    ActiveMerchant::Billing::Response.new(true, 'Bogus Gateway: Forced success', {}, :test => true, :authorization => '67890')
  else
    ActiveMerchant::Billing::Response.new(false, 'Bogus Gateway: Forced failure', :error => 'Bogus Gateway: Forced failure', :test => true)
  end
end
```
https://github.com/spree/spree/blob/master/core/app/models/spree/gateway/bogus.rb#L35-L42

`Payment#capture!` sends in cents instead of authorization as first param to `BogusGateway#capture`  which breaks.