ataru can handle multiple files and test methods are named after md files

- Now, ataru can handle multiple files:

```bash
$ ataru my_file.md my_file_2.md
```

- Test method names contain the filename of the markdown file.
You iterate twice over this array. Of course, in this example you won't get any performance penalties from doing this, but it is not very nice to read after all.

Maybe you could try to refactor this code to just iterate once over the array? One thing that could help would be to extract the block content into a method. This would have the advantage to call that method from a Rake task for instance ;-)