chore: Update metro-react-native-babel-preset to 0.49.0 🚀 (#52)

## The devDependency [metro-react-native-babel-preset](https://github.com/facebook/metro) was updated from `0.48.3` to `0.49.0`.
This version is **not covered** by your **current version range**.

If you don’t accept this pull request, your project will work just like it did before. However, you might be missing out on a bunch of new features, fixes and/or performance improvements from the dependency update.

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package.json

@@ -22,7 +22,7 @@
     "eslint": "^5.6.1",
     "flow-bin": "^0.84.0",
     "jest": "^23.6.0",
-    "metro-react-native-babel-preset": "^0.48.0",
+    "metro-react-native-babel-preset": "^0.49.0",
     "react": "16.6.0",
     "react-native": "^0.57.3",
     "react-test-renderer": "16.6.0",