code: function scale(path, ratio) {
              for (var i = 0, l = path.length; i < l; i++) {
                  var cur = path[i];
                  cur.x *= ratio;
                  cur.y *= ratio;
              }
  
              return path;
          }
docs: 对path进行缩放
  
  @param  {Array} path 轮廓数组
  @param  {number} ratio 缩放大小
  
  @return {Array}         path