Update TensorFlow version

[adamcpovey]

It's not possible to create a valid conda environment that satisfies all of this package's dependencies.

I can get it to run using the current version of TensorFlow, but that makes several complaints about using the wrong version. Any chance someone could download current versions of everything and retrain the nets (or find some way to convert the current nets into a newer file version)? Otherwise, this module can't be reconciled with the ORAC Python code.