Envify per Yoann Lecuyer

Stop being confused with your dev environments.

Configure the URL patterns for your environments and watch the Firefox theme changing every time you switch to another environment.

Firefox theme switch back to normal when you're browsing other sites.

* Before changing your global theme disable envify and enable it back after the change

Please report issues here: https://github.com/ylecuyer/envify/issues

Known bug or missing feature in the Firefox Dynamic Theme API that affect this addon:
* https://bugzilla.mozilla.org/show_bug.cgi?id=1415267
* https://bugzilla.mozilla.org/show_bug.cgi?id=1320585
* https://bugzilla.mozilla.org/show_bug.cgi?id=1458676