Add pip install

[Leguark]

set version number in setup.py, both for version and in download_url, also in the config file of the documentation

version='X.X', download_url='https://github.com/cgre-aachen/gempy/archive/X.X.tar.gz',

add new tag

$ git tag X.X -m "Add X.X tag for PyPI"

push git tag

$ git push --tags origin master

upload newest version to PyPi

First create the dist

python3 setup.py sdist bdist_wheel

Second upload the distributions

twine upload dist/*