Description:
    Copies an existing API version to a new API version.

Example:
    rails generate versionist:copy_api_version v2.0.0 V2_0_0 v3.0.0 V3_0_0

    This will do the following:

    route  api_version(:module => "V3__0__0", :header=>"Accept", :value=>"application/vnd.mycompany.com-v3.0.0") do
    end
    Copying all files from app/controllers/v2_0_0 to app/controllers/v3_0_0
    Copying all files from spec/controllers/v2_0_0 to spec/controllers/v3_0_0
    Copying all files from app/presenters/v2_0_0 to app/presenters/v3_0_0
    Copying all files from spec/presenters/v2_0_0 to spec/presenters/v3_0_0
    Copying all files from public/docs/v2.0.0 to public/docs/v3.0.0

Note: routes can only be copied with MRI Ruby 1.9 and above, as this feature relies on Ripper which is only available 
in stdlib in MRI Ruby 1.9 and above. Outside of routes copying, the other copy steps will work just fine in Ruby 1.8 and other
non-MRI Ruby implementations.
