Update metro (#311)

Summary:
- [ ] Solve failing JS travis job
Pull Request resolved: https://github.com/facebook/flipper/pull/311

Reviewed By: jknoxville

Differential Revision: D12822934

Pulled By: priteshrnandgaonkar

fbshipit-source-id: 2cc47372a3dde3500119e1e183aa97111cfe7f6a

static/package.json

@@ -13,7 +13,7 @@
     "@babel/plugin-transform-flow-strip-types": "^7.0.0",
     "@babel/plugin-transform-modules-commonjs": "^7.1.0",
     "@babel/preset-react": "^7.0.0",
-    "metro": "^0.48.1",
+    "metro": "^0.48.3",
     "recursive-readdir": "2.2.2"
   },
   "devDependencies": {}