Add css-mqpacker and postcss-custom-media

package.json

@@ -27,6 +27,7 @@
     "babel-preset-react": "6.23.0",
     "babel-preset-stage-0": "6.22.0",
     "classnames": "2.2.5",
+    "css-mqpacker": "^5.0.1",
     "front-matter": "2.1.2",
     "fs-extra": "2.0.0",
     "history": "4.5.1",
@@ -35,6 +36,7 @@
     "moment": "2.17.1",
     "postcss-cli": "2.6.0",
     "postcss-css-variables": "0.6.0",
+    "postcss-custom-media": "^5.0.1",
     "postcss-easy-import": "2.0.0",
     "postcss-nested": "1.0.0",
     "react": "15.4.2",

postcss.config.json

@@ -2,7 +2,9 @@
   "use": [
     "postcss-easy-import",
     "postcss-nested",
+    "postcss-custom-media",
     "postcss-css-variables",
+    "css-mqpacker",
     "autoprefixer"
   ],
   "autoprefixer": {