Python compiling instructions

Compiling with conda and other details...

https://github.com/vais-ral/CIL-Docs/blob/master/docs/developer_guide.rst

some personal bits from a chat with Edo about conda install:

create the environment

conda create -n py35 python=3.5 numpy=1.12

activate the environment

build the package

conda build conda-recipe/ --numpy 1.12 --python 3.5 -c conda-forge #install the package conda install tomophantom=1.0 --use-local --force