[FEATURE] add very basic autoprefixer support

core/tasks/css.js

@@ -4,6 +4,7 @@ const fs = require('fs');
 const path = require('path');
 const globby = require('globby');
 const postcss = require('postcss');
+const autoprefixer = require('autoprefixer');
 const util = require('util');
 const chalk = require('chalk');
 
@@ -53,7 +54,9 @@ module.exports = class Css extends Task {
 			this._logger.error(_error);
 		}
 
-		fs.writeFile(_output, result.css, _error => {
+		let css = await postcss([autoprefixer]).process(result.css);
+
+		fs.writeFile(_output, css, _error => {
 			if (_error) {
 				return this._logger.error(_error);
 			}

package.json

@@ -15,6 +15,7 @@
     "node": "~10.9.0"
   },
   "dependencies": {
+    "autoprefixer": "^9.1.3",
     "chalk": "^2.4.1",
     "globby": "^8.0.1",
     "log-symbols": "^2.2.0",