Imported overlord solution

Joe/Sophia,
I spent this morning re-doing my level_up fork and branches. I believe it is correct now. Each task now has its own branch containing nothing other than changes pertinent to the task itself.

I'm resubmitting a code-review pull-request for overlord.

Zamir
Still, assertions in a `Given` are not great :'(

Maybe...

```
Given(/I try to create a bomb with bad code ABCD/) do
  @attempted_code = -> { Bomb.new(activation_code: 'ABCD')
end

Then(/My attempt raises an ArgumentError/) do
  expect(&@attempted_code).to raise(ArgumentError)
end
```