Solve conflict between ACI and base methods in MapieTimeSeriesRegressor

[BaptisteCalot]

Description

This PR is to fix issue 447 where the method of MapieTimesSeriesRegressor is "aci" but when we use the fit method of MapieRegressor, the method become "base"

Type of change

• Bug fix : In MapieRegressor, when cv is prefit or split and method different from "naive" or "plus", you don't force the method to become "base"

How Has This Been Tested?

• [x] re-create example and make sure it works:
• [x] Build instance of MapieTimeSeriesRegressor with method "aci"
• [x] Fit instance (with fit method from MapieRegressor)
• [x] Update the instance
• [x] Finaly check the instance's method and see if it still "aci"

Checklist

• [x] I have read the contributing guidelines
• [x] I have updated the HISTORY.rst and AUTHORS.rst files
• [x] Linting passes successfully : make lint
• [x] Typing passes successfully : make type-check
• [x] Unit tests pass successfully : make tests
• [x] Coverage is 100% : make coverage
• [x] Documentation builds successfully : make doc

[LacombeLouis]

Hey @BaptisteCalot, Thank you for your contribution! Make sure to make the tests as generic as possible to check for possible other bugs.

[BaptisteCalot]

Yes indeed, thank you for the remark ! 😉

[LacombeLouis]

Hey @BaptisteCalot, thank you for the generalized test! Make sure to tick all the boxes! Don't forget to:

• [ ] I have updated the HISTORY.rst and AUTHORS.rst files