Adds MobiletNetV3 to applications (#176)

* Adds MobiletNetV3 to applications

* Update styles

* Fix the reshape for 'channels_first'

* Fix PEP8

Co-authored-by: Aleksandr <[email protected]>
Co-authored-by: Taehoon Lee <[email protected]>

Author: DrSlink

Diff for: README.md

@@ -53,6 +53,8 @@ and is distributed under the MIT license.
 | [MobileNetV2(alpha=1.0)](keras_applications/mobilenet_v2.py)   |  224  | 71.336      | 90.142      | 3.5M   | 2.3M   | [[paper]](https://arxiv.org/abs/1801.04381) [[tf-models]](https://github.com/tensorflow/models/blob/master/research/slim/nets/mobilenet/mobilenet_v2.py) |
 | [MobileNetV2(alpha=1.3)](keras_applications/mobilenet_v2.py)   |  224  | 74.680      | 92.122      | 5.4M   | 3.8M   | [[paper]](https://arxiv.org/abs/1801.04381) [[tf-models]](https://github.com/tensorflow/models/blob/master/research/slim/nets/mobilenet/mobilenet_v2.py) |
 | [MobileNetV2(alpha=1.4)](keras_applications/mobilenet_v2.py)   |  224  | 75.230      | 92.422      | 6.2M   | 4.4M   | [[paper]](https://arxiv.org/abs/1801.04381) [[tf-models]](https://github.com/tensorflow/models/blob/master/research/slim/nets/mobilenet/mobilenet_v2.py) |
+| [MobileNetV3(small)](keras_applications/mobilenet_v3.py)       |  224  | 68.076      | 87.800      | 2.6M   | 0.9M   | [[paper]](https://arxiv.org/abs/1905.02244) [[tf-models]](https://github.com/tensorflow/models/tree/master/research/slim/nets/mobilenet/mobilenet_v3.py) |
+| [MobileNetV3(large)](keras_applications/mobilenet_v3.py)       |  224  | 75.556      | 92.708      | 5.5M   | 3.0M   | [[paper]](https://arxiv.org/abs/1905.02244) [[tf-models]](https://github.com/tensorflow/models/tree/master/research/slim/nets/mobilenet/mobilenet_v3.py) |
 | [DenseNet121](keras_applications/densenet.py)                  |  224  | 74.972      | 92.258      | 8.1M   | 7.0M   | [[paper]](https://arxiv.org/abs/1608.06993) [[torch]](https://github.com/liuzhuang13/DenseNet/blob/master/models/densenet.lua) |
 | [DenseNet169](keras_applications/densenet.py)                  |  224  | 76.176      | 93.176      | 14.3M  | 12.6M  | [[paper]](https://arxiv.org/abs/1608.06993) [[torch]](https://github.com/liuzhuang13/DenseNet/blob/master/models/densenet.lua) |
 | [DenseNet201](keras_applications/densenet.py)                  |  224  | 77.320      | 93.620      | 20.2M  | 18.3M  | [[paper]](https://arxiv.org/abs/1608.06993) [[torch]](https://github.com/liuzhuang13/DenseNet/blob/master/models/densenet.lua) |

Diff for: keras_applications/__init__.py

@@ -57,6 +57,7 @@ def correct_pad(backend, inputs, kernel_size):
 from . import xception
 from . import mobilenet
 from . import mobilenet_v2
+from . import mobilenet_v3
 from . import densenet
 from . import nasnet
 from . import resnet