Cln neural networks module
In this branch, I have removed several submodules from the neural_networks module, including the old cnn and edtcnn modules with respective test sets and some of the new architectures present in the enh_nn_structures that won't be included in the next release.
Other changes include:
- a few corrections regarding tensorflow 2.0
- a bug fix in the BatchGenerator class
- a circular dependency in the data_handling modules was removed
- Most broken tests have been fixed
At this point, only one test is failing.
- All tests are passing, including doctests
- updated the docker image to use ketos 2.0.0b0 (beta)