Warning: end value has mixed support

[Samuelfaure]

Après update de 1.1.6 à 1.2.2 :

 warning  in ./node_modules/template.data.gouv.fr/dist/main.css

Module Warning (from ./node_modules/postcss-loader/src/index.js):
Warning

(1324:11) end value has mixed support, consider using flex-end instead

(compilation sur projet avec vue-cli-3)

[guillett]

Should be fixed with #138