Added an environment.yml configuration for easy install via conda environments

[LukasMosser]

I've created a small environment.yml file to create a geostats environment.

Allows simple install via:

conda env create -f environment.yml

and activate new environment via:

conda activate geostats
jupyter notebook

Ran the notebooks to check if it works and added a small readme note in the installation README.md.

If there are any more libraries that should be added, I can modify the pull request.

Tested on Ubuntu 16.04.