A Massive Improvement

Due to my stupid mistake related to the configuration schema loading, this release is broken. Upgrade to https://github.com/fbiville/headache/releases/tag/1.0.0-M02 at least!

A lot has been done since the last version:

• [8372f00] there is now a code of conduct
• [#5][#9] Copyright years are now based on versioning information and the lowest bound, if found, is always preserved
• [#14] headache tracks its last execution and only consider source files that have changed since
• [#20] Contributing new comment styles should now be easier (see #22 - help much appreciated)
• [#16] A first step towards license switch has been implemented, although a big question (#29) remains open (input much appreciated as well)
• [#3] Several improvements have been gradually pushed to enhance header detection (although it's still a big ball of regex 😱)
• dry-run mode has been implemented and finally removed as it has been deemed too complex and without much value (project maintainers can discard the changes they do not want!)
• [#24] headache configuration is now validated against a JSON schema

The objectives to reach for 1.0.0 are about (at least for now):

• [#3] moving towards a reliable header detection
• [#22] supporting more comment styles
• [#16] improving the license switch journey (depends on #29)
• [#23] allowing to co-locate multiple configurations for polyglot projects

They will be released in subsequent milestones.

Any help is welcome and much appreciated, make sure to watch the issues and grab the low hanging fruits 🌴