Conda publish

[benoit-cty]

Technical changes

• Publish to conda
• Test that the package works in Windows
• Fix duplicate CI runs (not related to conda).
• Add documentation on how to use with Conda in README.md
• Add documentation on how to publish to Conda in .conda/README.md

[coveralls]

Coverage remained the same at 78.92% when pulling e5845ff5f9b5873e17fd462d19374e4cb2d3cd8b on conda_publish into 752c3befde4ee2d5acb36cf5ae9a35ea2e9f976a on master.

[benoit-cty]

@sandcha : I've done all the changes.

[MattiSG]

I'm a bit surprised that this PR has not been merged while Core is seemingly already published 🤔 😅

[benoit-cty]

I'm a bit surprised that this PR has not been merged while Core is seemingly already published thinking sweat_smile

Hi Matti, It's because Core has it's own FeedStock that create a PR in https://github.com/conda-forge/openfisca-core-feedstock/pulls when a new package is detected on PyPi to publish it to channel conda-forge.

This PR is for automatically publish to channel openfisca in CI and document all the process.

[sandcha]

Running python3 .github/get_pypi_info.py -p OpenFisca-Core to check why the conda build failed generates this meta.yaml where the comment is already updated as in this (local) example:

###############################################################################
## File for Anaconda.org
## WARNING : strings 35.8.1, https://files.pythonhosted.org/packages/d9/00/dd774c31b43daca0c844e21f7b56389913996bf7fe3f5e3f2368ec78fd9e/OpenFisca-Core-35.8.1.tar.gz, b843c814015cc5a8e345f342b56906ba2c986d85270acecef9e32a3aea09ef35 and     - dpath <3.0.0,>=1.5.0
    - nptyping ==1.4.4
    - numexpr <=3.0,>=2.7.0
    - numpy <1.21,>=1.11
    - psutil <6.0.0,>=5.4.7
    - pytest <6.0.0,>=4.4.1
    - PyYAML >=3.10
    - sortedcontainers ==2.2.2
    - typing-extensions ==3.10.0.2
 will be replaced
## by CI script get_pypi_info.py, leave them as is.
###############################################################################
...

Then running conda build .conda on local machine produces the error detected in CI.