参考文档
- https://arxiv.org/abs/1801.04381v2
 - https://www.zhihu.com/question/265709710 如何评价mobilenet v2 ?
 - http://blog.csdn.net/u014380165/article/details/79200958 MobileNet v2 算法笔记
 - http://blog.csdn.net/u011995719/article/details/79135818 轻量化网络:MobileNet-V2
 - https://zhuanlan.zhihu.com/p/33075914 MobileNet V2 论文初读