Electricity mix flexibility

[adrienbanse]

This PR implements

• ecologits/mix_repository.py A mix repository from the ADEME database csv ecologits/data/mixes.csv
• The possibility for the user to choose a mix when calling llm_impacts
• Modify and implement tests

[samuelrince]

Thanks @adrienbanse, this looks good!

One remark about on the usage of pycountry. As I can see, we only use the library to check if a country code exists, right? But, we could also perform this check by just looking if the code exists in the electricity mix repository. Thus, the pycountry dependency is not really necessary, so I think we can remove it. Generally speaking, the less dependence we have the better, I would say! :)

If we want to support other country code formats, we can also pre-compute them in the file. I am working the ecologits-data repository mainly for the models, but we can integrate this file later with some logic.

We can work on the interface on how to change the country code in another PR about "configuration management", what do you think?

[adrienbanse]

@samuelrince Agreed, I removed pycountry from the PR.

Yes let's merge it as it is now, and let's open a PR in ecologits-data to handle alpha-2, alpha-3, official names etc. (and use pycountry there). I think we can even handle emoji flags 😄

Yes this PR is only for the implementation of the flexibility, now I'll start to work on a general configuration in Ecologits.init() for choosing the mix, maybe a verbose parameter, ...