Generates three random slots
Added win logic and improved names.

This starts to feel like a SlotMachine. However, there is still a
problem. I don't know how to redirect the output to the input, I mean,
I don't know how to keep state value such as `credits`. 'The Yampa
Arcade' article seems like a nice place to look for the answer.
The traces are now more similar to the original ones.
Statefull credits.
Now, random stuff is something internal to the network.
Added error flag, to determine no credits situation.
GameInput has been simplified.
GameOutput has been simplified as well.
Switcher applied but does not work. Alternatives?
SlotMachine up & running.

After many workarounds, I was able to provide an implementation for
the SlotMachine application. Honestly, I don't know if it's because of
the current application or Yampa is really annoying to deal with.

The major problem was the read-and-then-write situation. For example,
the credit. First, you have to read it, in order to determine if the
player can play or not. Then, you have to update it (spend credit or
win prize). Well, this was impossible to deploy, so I have to add many
workarounds (for instance: negative credits).

In general, everything is quite weird, because you have to think in
your application as a circuit, where some components can be stateful
(accumHold) in a strange way. I think that the switching has to
provide many facilities and I have to read deeper in that line to
improve my skills with this technology.
Merge pull request #73 from jeslg/slot-yampa

Slot yampa