chore(package): update react-cosmos to version 4.8.1

Closes #154

Author: greenkeeper[bot]

package.json

@@ -91,7 +91,7 @@
     "eslint-plugin-react-native": "^3.2.0",
     "firebase-server": "^0.12.0",
     "git-scripts": "^0.2.1",
-    "react-cosmos": "^3.1.1",
+    "react-cosmos": "^4.8.1",
     "react-test-renderer": "^16.1.1",
     "redux-devtools": "^3.4.1",
     "redux-mock-store": "^1.3.0",