Remove base attribute from ParameterScaleBracket

[benjello]

Depends on #1160

Breaking changes

• ParameterScaleBracte:
  • Remove base attribute

This attribute is unclear and was used only for some French social security contributions

[MattiSG]

Nice! Less complexity is always good 😄

This will have to be a breaking change.

[bonjourmauko]

Too late to finally know what it did? I always thought it was some sort of bit wise feature.

[benjello]

@maukoquiroga : some french social security contribution (AGIRC-ARRCO, IRCANTEC, CSG, CRDS) have a theoretical rate and an actual rate with a corrective coefficient. We used base to host the latter to stick to the "law of unique source of truth". But not systematically, resulting in more confusion than convenience. So I prefer to remove it completely to force people follow the rule "explicit is better than implicit".

[coveralls]

Coverage increased (+0.05%) to 77.666% when pulling 26c37c0 on remove-taxscale-bracket-base into 0caf9fc on master.

[benjello]

@maukoquiroga : argh test fails after the bump ...

[bonjourmauko]

This was failing because of incompatible caches. Now just because its a major, requires #1160