Setup file

[conor-james-sheehan]

The current setup.py file has its Tensorflow requirement as
"tensorflow>=v1.1.0",
meaning that when I pip install the package from source in a fresh conda environment it installs the newest TensorFlow version (2.1).

I think what you want here is
"tensorflow>=1.1.0, <=1.15".

Additionally, after having done this, my install threw an error relating to mpi4py. This was fixed by me installing this package separately (not sure whether this is a problem with the setup or just an issue with my environment).