fix(deps): pin dependency react-router-dom to 5.2.0

package.json

@@ -55,7 +55,7 @@
     "lodash.defaults": "4.0.1",
     "lodash.get": "^4.4.2",
     "react-helmet": "5.2.0",
-    "react-router-dom": "^5.2.0",
+    "react-router-dom": "5.2.0",
     "scratch-parser": "5.0.0",
     "scratch-storage": "0.5.1"
   },