Merge pull request #6 from martco/master

Guard::Cucumber::Focuser
Update CHANGELOG.
Make Fakefs available on Travis CI.
Remove useless return value in the spec.
Minor Focuser refactorings.

* Use inject() in the `#focus` method.
* Strings without interpolation are single quoted.
* Do not nest multiple '#describes' (A describe is only for
  the class and method, everything else is a context).
Minor runner spec refactorings.

* Strings without interpolation are single quoted.
* Stub system call.
Remove fakefs.

FakeFS doesn't work on Rubinius properly,
so this commit removes it and uses normal
stubbing to fake the file content.
Update Travis configuration.
Fix wrong YARDOC param name.
Minor code style changes.
Add Bundler as dev dependency.
Use development group in gemfile.
Use eql matcher.
Ignore Rubinius errors on Travis.

Specs are passing fine locally on Rubinius,
so allow it to fail on Travis until fixed.
Release 1.3.0
scan_for_focus_path should return an empty array if path is a directory

When I have set `focus_on`, and I run all tests, then a directory path may be sent to Focuser#scan_for_focus_path. This method tries to call File#gets on the path, and ruby throws a "Is a directory" error.

This patch simply returns an empty array if the file is a directory.