def files
      @files ||= Dir.glob(File.join(@root, '**/*'), GLOB_FLAGS).select do |path|
        File.file?(path) && path !~ IGNORE_REGEX
      end
    end
def files
      @files ||= Dir.glob(File.join(@root, '**/*'), GLOB_FLAGS).select do |path|
        File.file?(path) && path !~ IGNORE_REGEX
      end
    end
Public: Initialise the ProjectTree instance.

 root - The absolute path to the root of the project within which any file
        operations should be performed.
 Public: Get the full list of files in the project tree, with any files
 ignored by Git, SVN or some other VCS removed from the list.

 Returns an Array of Strings where the strings are paths within the
 project.