Update foodie to use latest gems.

Also removed the aruba step difinition extentions, as that step is
now included within aruba!
Updated the guide inline with changes to the example, ie:

* Aruba now contains step definitions for reading the text file

Other changes:
* Because my editor removes whitespace, there is a few cleanup changes
* Changed the markdown syntax on some /path/to/text_file.txt, as some
  were breaking because of the inclusion of an underscore
Merge pull request #38 from charlespeach/feature/update-gem-development

Update foodie gem and guide, removed aruba step extensions