refactor(postcss): use pkg browserslist in postcss config

Author: dolymood

package.json

@@ -139,7 +139,6 @@
     "> 1%",
     "last 2 versions",
     "not ie <= 8",
-    "not ie <= 11",
     "Android >= 4.0",
     "iOS >= 8"
   ]

postcss.config.js

@@ -1,12 +1,7 @@
 module.exports = {
   plugins: [
     require('autoprefixer')({
-      browsers: [
-        "> 1%",
-        "last 2 versions",
-        "not ie <= 8",
-        "iOS 8"
-      ]
+      browsers: require('./package.json').browserslist
     })
   ]
 }