Update deps

Author: th0r

.babelrc

@@ -7,6 +7,7 @@
     }]
   ],
   "plugins": [
-    ["@babel/plugin-proposal-class-properties", {"loose": true}]
+    ["@babel/plugin-proposal-class-properties", {"loose": true}],
+    ["@babel/plugin-proposal-private-methods", {"loose": true}]
   ]
 }

.npm-upgrade.json

@@ -13,4 +13,4 @@
       "reason": "Current version of Webpack Dev Server doesn't work with v4"
     }
   }
-}
+}