remove trailing comma from package.json

Author: amrlabib

package.json

@@ -30,6 +30,6 @@
  "homepage": "https://github.com/amrlabib/react-native-appstate-hook#readme",
  "peerDependencies": {
  "react": "^16.8.0",
- "react-native": "0.59.0-rc.1",
+ "react-native": "0.59.0-rc.1"
  }
 }