Update the overlord solution

As another tip for cucumber tests, these steps are easy to define, but hide the application logic behind multiple steps. For instance, the following set of steps:

```
Then I enter activation code "4321"
When I click "Activate"
```

Should really be a single step:

```
When I try to activate the bomb using the code "4321"
```

Since tests serve a significant role as documentation, this is more important than the slight increase in difficulty of step implementation.