def remove(filename)
      path = File.join(dir, filename)
      gzip = "#{path}.gz"
      logical_path = files[filename]['logical_path']

      if assets[logical_path] == filename
        assets.delete(logical_path)
      end

      files.delete(filename)
      FileUtils.rm(path) if File.exist?(path)
      FileUtils.rm(gzip) if File.exist?(gzip)

      save

      logger.info "Removed #{filename}"

      nil
    end
def remove(filename)
      path = File.join(dir, filename)
      gzip = "#{path}.gz"
      logical_path = files[filename]['logical_path']

      if assets[logical_path] == filename
        assets.delete(logical_path)
      end

      files.delete(filename)
      FileUtils.rm(path) if File.exist?(path)
      FileUtils.rm(gzip) if File.exist?(gzip)

      save

      logger.info "Removed #{filename}"

      nil
    end
Removes file from directory and from manifest. `filename` must
 be the name with any directory path.

   manifest.remove("application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js")