chore(package): update @types/react-native to version 0.60.8 (#662)

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
   "devDependencies": {
     "@types/eslint": "^6.1.0",
     "@types/react": "16.9.2",
-    "@types/react-native": "0.60.7",
+    "@types/react-native": "0.60.8",
     "babel-eslint": "^10.0.2",
     "eslint": "^6.1.0",
     "eslint-config-standard": "^14.0.0",