Updated sass & css loaders.

package.json

@@ -34,13 +34,13 @@
     "babel-loader": "~8.0",
     "compression-webpack-plugin": "~2.0",
     "cross-env": "^6.0.3",
-    "css-loader": "^3.2.0",
+    "css-loader": "^3.6.0",
     "file-loader": "^4.2.0",
     "friendly-errors-webpack-plugin": "~1.7",
     "html-webpack-plugin": "~3.2",
     "mini-css-extract-plugin": "~0.5",
     "optimize-css-assets-webpack-plugin": "~3.2",
-    "sass-loader": "~7.1",
+    "sass-loader": "~9.0.2",
     "uglifyjs-webpack-plugin": "~1.2",
     "url-loader": "^2.2.0",
     "vue-loader": "~15.6",