update devDependencies

package.json

@@ -28,12 +28,12 @@
     "babel-core": "^6.22.1",
     "babel-loader": "^6.2.10",
     "babel-preset-es2015": "^6.22.0",
-    "css-loader": "^0.26.1",
+    "css-loader": "^0.27.1",
     "exports-loader": "^0.6.3",
     "file-loader": "^0.10.0",
     "node-sass": "^4.5.0",
     "postcss-loader": "^1.2.2",
-    "sass-loader": "^4.1.1",
+    "sass-loader": "^6.0.3",
     "style-loader": "^0.13.1",
     "url-loader": "^0.5.7",
     "webpack": "^2.2.1",