The version of tensorflow need to be updated in ReadMe

[GuanxiongLiu]

In my test, this project need the api version 1.0 for tensorflow. The ReadMe file need to update this information for user's convenience.

Thanks

[zhouliang-yu]

Yes, but if you are using the latest or 2.0+ version, you can just replace
from tensorflow.contrib import layers to
from tensorflow.keras import layers