Update dependencies

Author: LasaleFamine

package.json

@@ -54,17 +54,17 @@
     "fs-extra": "4.0.1",
     "loader-utils": "1.1.0",
     "parse5": "3.0.2",
-    "postcss": "6.0.9",
+    "postcss": "6.0.11",
     "postcss-load-config": "1.2.0"
   },
   "devDependencies": {
-    "autoprefixer": "7.1.2",
+    "autoprefixer": "7.1.3",
     "ava": "0.22.0",
     "coveralls": "2.13.1",
     "execa": "0.8.0",
-    "nyc": "11.1.0",
+    "nyc": "11.2.1",
     "text-loader": "0.0.1",
-    "webpack": "3.5.5",
+    "webpack": "3.5.6",
     "xo": "0.18.2"
   }
 }