Automatically validate parameter declaration dates

[MattiSG]

Hi there!

I really enjoy OpenFisca, but I recently encountered an issue.

Here is what I did:

• Make a mistake in describing parameters: invert month and day numbers in dates (Corrige le format de certaines dates openfisca-france#1522).

Here is what I expected to happen:

• Automated tests tell me that month number 31 doesn't exist in a year and that I probably inverted day and month in my date declaration.

Here is what actually happened:

• Tests passed and we deployed a broken country package version.

Here is data (or links to it) that can help you reproduce this issue:

openfisca/openfisca-france#1522

Context

I identify more as a:

• Business expert (I create tests and model legislation).
• Developer (I create tools that use the existing OpenFisca code).

[bonjourmauko]

Reproduced here.

[bonjourmauko]

Sorry and I think this is a bug actually, not a new feature, as it should already be checked here