move css minification from postcss to webpack (for better source maps)

postcss.config.js

@@ -1,42 +0,0 @@
-module.exports = {
-  options: {
-    map: false,
-  },
-  plugins: [
-    require("postcss-import")(),
-    require("autoprefixer")(),
-    require("postcss-svgo")({
-      encode: true,
-    }),
-    require("postcss-focus")(),
-    require("postcss-color-rgba-fallback")({
-      properties: [
-        "background-image"
-      ],
-    }),
-    require("postcss-combine-duplicated-selectors")(),
-    require("postcss-normalize-charset")(),
-    require("postcss-clean")({
-      compatibility: "*",
-      level: 1,
-      processImport: false,
-      format: {
-        breaks: {
-          afterAtRule: true,
-          afterBlockBegins: true,
-          afterBlockEnds: true,
-          afterComment: true,
-          afterRuleEnds: true,
-          beforeBlockEnds: true,
-        },
-        spaces: {
-          beforeBlockBegins: true,
-        },
-        semicolonAfterLastProperty: true,
-      },
-    }),
-    require("postcss-reporter")({
-      clearReportedMessages: true,
-    }),
-  ],
-};