def write_asset(environment, asset)
      filename = path_for(environment, asset)
      FileUtils.mkdir_p File.dirname(filename)
      asset.write_to filename
      asset.write_to "#{filename}.gz" if gzip?(filename)
      asset.digest
    end
def write_asset(environment, asset)
      filename = path_for(environment, asset)
      FileUtils.mkdir_p File.dirname(filename)
      asset.write_to filename
      asset.write_to "#{filename}.gz" if gzip?(filename)
      asset.digest
    end
Writes the asset to its destination, also
 writing a gzipped version if necessary.