fix: mobx-react-devtools is a dev dependancy #10275

package.json

@@ -68,6 +68,7 @@
     "karma-webpack": "^2.0.4",
     "lint-staged": "^6.0.0",
     "load-grunt-tasks": "3.5.2",
+    "mobx-react-devtools": "^4.2.15",
     "mocha": "^4.0.1",
     "ng-annotate-loader": "^0.6.1",
     "ng-annotate-webpack-plugin": "^0.2.1-pre",
@@ -140,7 +141,6 @@
     "lodash": "^4.17.4",
     "mobx": "^3.4.1",
     "mobx-react": "^4.3.5",
-    "mobx-react-devtools": "^4.2.15",
     "mobx-state-tree": "^1.3.1",
     "moment": "^2.18.1",
     "mousetrap": "^1.6.0",