Rename hostsfile_path method

Rename the hostsfile_path method to get_hostsfile_path, and replace
references to the method with the variable @hostsfile_path
Add windows support

Adding a platform check and returning the windows path when appropriate.
Clean up Windows support
- Use value_for_platform instead of conditions
- Use ohai data instead of ENV
- Add specs and travis support
Add column formatting in README [ci skip]
Updated CHANGELOG to include master changes [ci skip]
Version bump for latest release
Add rehl as platform_family
Version bump and update email
Just default to /etc/hosts if not on Windows
Fatal if hostsfile does not exist. Fixes #19.
Write out priorities as part of the comment so they are read in subsequent Chef runs. Fixes #20
Don't update rubygems and Chef anymore
Fix broken 1.8.7 tests on Travis
Set @node first, since it's used in hostsfile_path
Force priority to_i and hostname to_s
Major version bump b/c of API change
Update README.md
Use https for Rubygems
Use chefspec master
Try upgrading to newest rubygems