Publish to PyPI

[Jorge Carrasco]

This is pending on pypi/support#1124

For users that stumble upon this issue, please install it from source, as any normal python package:

git clone https://github.com/ginkgobioworks/geckopy
cd geckopy
pip install .
# to also install pytfa (optional dep for thermodynamics integration)
pip install ".[pytfa]"