Efficientnet's BASE_WEIGHTS_PATH points to external release

[xhluca]

Summary

It seems like in the case of DenseNet and ResNet, the weights are released on the keras-applications repo: https://github.com/keras-team/keras-applications/blob/bc89834ed36935ab4a4994446e34ff81c0d8e1b7/keras_applications/densenet.py#L27-L29

https://github.com/keras-team/keras-applications/blob/bc89834ed36935ab4a4994446e34ff81c0d8e1b7/keras_applications/resnet_common.py#L41-L43

In the case of EfficientNet, the weights come from a fork of keras-applications: https://github.com/keras-team/keras-applications/blob/master/keras_applications/efficientnet.py#L33-L35

Although the hashes should ensure the file downloaded is authentic, is there a plan for handling release URL changes?

Environment

• Python version: N/A
• Keras version: N/A
• Keras-applications version: Master
• Keras backend with version: N/A

Logs or source codes for reproduction