Autofix should support error if not handled

[devTeaa]

Hi currently if I create a autofix func and doesn't handle a value (for ex: color: blue), I would like to have an option to throw error that the value blue is not fixable from the function, I have tried implementing one here #250, sorry for not raising issue beforehand

reference:

• https://github.com/AndyOGo/stylelint-declaration-strict-value/blob/master/test/auto-fix-func.js
• https://github.com/AndyOGo/stylelint-declaration-strict-value/blob/master/test/helpers/auto-fix-func.js

[AndyOGo]

@devTeaa Thank you very much for the issue. It's released with v1.9.0

[devTeaa]

Thanks a lot @AndyOGo