Revert "Changed browsers param for autoprefixer to browserslist"

This reverts commit dc97ffa.

postcss.config.js

@@ -0,0 +1,32 @@
+/*
+Copyright 2018 Google LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+module.exports = {
+    plugins: {
+        autoprefixer: {
+            browsers: [
+                "Android 2.3",
+                "Android >= 4",
+                "Chrome >= 20",
+                "Firefox >= 24",
+                "Explorer >= 8",
+                "iOS >= 6",
+                "Opera >= 12",
+                "Safari >= 6"
+            ]
+        }
+    },
+}