{
  "name": "Example",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "react-native start"
  },
  "dependencies": {
    "react-native": "^0.16.0",
    "react-native-admob": "0.2.0"
  }
}

{
  "name": "Example",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "react-native start"
  },
  "dependencies": {
    "react-native": "0.19.0",
    "react-native-admob": "../"
  }
}

Use git project as dependency in example project
Use git project as dependency in example project