Need to modify this to hide the output from actually being output.

Maybe something like the following:

```ruby
lambda { hide_output { subject.parse(["-v"]) } }.should raise_error(SystemExit)
```

Now this means that ```hide_output``` will have to be defined similar to the ```capture_output``` method in ```spec_helper.rb``` and it should probably do exactly the same thing as ```capture_output``` except it shouldn't return a value and it should NOT rescue SystemExit.