message: add vector-icons to devDeps
diff: "jest": "17.0.0",
  "react": "^15.4.2",
  "react-native": "^0.39.2",
  - "react-test-renderer": "^15.3.2"
  + "react-test-renderer": "^15.3.2",
  + "react-native-vector-icons": "~4.0.0"
  },
  "directories": {},
  "dist": {
  