Maintenance Release 1.3.11

Maintain release for old TF versions.

This is an incomplete list among the many features added.

• New support
  • TimeDistributedLayer applies a function to every timestep of the input. @zsdonghao
• Update
  • fix PReluLayer typo by @geometrikal
  • update BatchNormLayer for TF 0.12.1 @zsdonghao @nebulaV
• Documentation
  @zsdonghao