Mmdnn

[VGG 19](http://arxiv.org/abs/1409.1556.pdf) | √ | √ | √ | √ | √ | √
[MobileNet_v1](https://arxiv.org/pdf/1704.04861.pdf)| × | √ | √ | × (No Relu6) | ×

[ResNet V1 50](https://arxiv.org/abs/1512.03385) | × | √ | √ | o | √ | √

Initial support for PyTorch1.5.1 .

Updated dependencies：
* NumPy 1.15.4 =>1.18.2
* Pillow 5.2.0=>6.2.2
* TensorFlow 1.13.1 =>1.15.2
* Keras 2.2.4 =>2.2.5
* MXNet 1.2.0 =>1.6.0
* CNTK 2.6 =>2.7
* SciPy==1.4.1
* Scikit-image==0.16.2

Bug Fixed and Improvement:
* Fix op [LRN]
* Fix tensorflow_parser[Slice], [DepthwiseConv2dNative]
* Fix caffe_emitter[Relu6]
* Add op [Unpool]
* Add keras [Affine]
* Add tensorflow [AddV2], [FusedBatchNormV3]
* Stability improvements.

Tips:
We recommand Python 3.6 since Python 2 has retired. If you experience incompatibility with other Python 3.x versions, please submit an issue.