def read_template
      path = @template_filepath
      if @gem_included_template
        relative_path = "../../#{@template_filepath}"
        path = File.expand_path(relative_path, File.dirname(__FILE__))
      end
      @html = File.read(path)
    end
def read_template
      path = @template_filepath
      if @gem_included_template
        relative_path = "../../#{@template_filepath}"
        path = File.expand_path(relative_path, File.dirname(__FILE__))
      end
      @html = File.read(path)
    end
Reads the @template_filepath file and sets @html to it's contents.
 The correct filepath is decided on based on wether or not the template is
 built into the gem or on the user's local filesystem.