Sync with keras-team/keras

Sync with the original keras repo. Fixes serialization bugs and tests.

Several fixes

2.2.5

Fix tests

Up-to-date with upstream

2.2.4.2

Update update_apy.py

Up-to-date with upstream. Different get_updates and optimizers.

Different get_updates and optimizers

Working version for Keras Tiramisu

Adapted for usage with https://github.com/beareme/keras_semantic_segmentation

Stable version 16th April 2018

2.0.8

Fixbug MultiHeadAttention layer

Working TF backend

2.0.7

Allow arbitrary input length in RNNs (TF backend)

Stable version at 2nd Oct (Keras 2.0.6)

Added required endline

Keras 2.0

ConditionalLSTMs bug

Stable Keras 1.2. Prior to switch to Keras 2.0.

1.4

Update README.md