Overlord - Iteration 2

In this second iteration, I made all of the changes suggested in the first iteration, except changing the case statement in `bomb.rb`. After discussing it with Joe, he said it was okay for this implementation.

Below are the main changes I made in this iteration:

1. Create another feature spec: deactivate_bomb.feature.

2. Add descriptions to Feature files.

3. Make methods private in `bomb.rb` that aren't used outside the class.

4. Condensed many of the specs in my Feature files to read better; in the process I moved the detailed steps of many Givens, Whens, and Thens to `add_task_steps.rb`.

5. Reorganized `add_task_steps.rb` to place Givens, Whens, and Thens in order.

6. I improved the logic (I think!) of determining whether to use the user supplied codes or to use the default codes with the following methods: `#valid_code' and `#initialize`.

7. Added a Feature to check that the bomb is unusable after it explodes.

Thanks!
If we had one file, namely index.erb. we could have them DRY some stuff up and have all respective views inherit the properties of that file.

edit: just saw that there is an index.erb file.. looks like we're on the right track

This would allow us to have one file with the <html> <head> tags etc, rather than multiple.

see my example,

https://github.com/JimCouch/level_up_exercises/blob/master/overlord/views/index.erb