fix postcss

package.json

@@ -103,21 +103,12 @@
     "markdown-it-anchor": "^2.5.0",
     "markdown-it-container": "^2.0.0",
     "mocha": "^3.2.0",
-    "pixrem": "^3.0.0",
     "postcss": "^5.1.2",
-    "postcss-calc": "^5.0.0",
-    "postcss-css-reset": "^1.0.2",
     "postcss-easy-import": "^2.0.0",
-    "postcss-initial": "^1.3.1",
-    "postcss-inline-svg": "^1.4.0",
-    "postcss-loader": "^0.13.0",
+    "postcss-loader": "^1.3.3",
     "postcss-neat": "^2.5.2",
     "postcss-pseudo-class-any-link": "^1.0.0",
-    "postcss-sass-color-functions": "^1.1.0",
     "postcss-scss": "^0.1.7",
-    "postcss-shape": "^0.0.1",
-    "postcss-short": "^1.4.0",
-    "postcss-utils": "^1.0.1",
     "precss": "^1.4.0",
     "prismjs": "^1.5.1",
     "progress-bar-webpack-plugin": "^1.9.3",