         src: '**/*.coffee'     # traverse *.coffee files relative to cwd
         dest: 'build/test'     # destination for compiled js files
         ext: '.js'             # file extension for compiled files
-        filter: hasChanged("coffee.test")
         options:
           sourceMap : true
       demo:

        src: '**/*.coffee'     # traverse *.coffee files relative to cwd
        dest: 'build/demo/js'  # destination for compiled js files
        ext: '.js'             # file extension for compiled files
        filter: hasChanged("coffee.demo")
        options:
          sourceMap : true
      spectrogram:

          cwd: 'demo'
          src: ['**/*.html', '**/*.js', '**/*.css', '**/*.png', '**/*.py']
          dest: 'build/demo'
          filter: ['isFile']
        ]
      vendor:
        files: [
