update yarn lockfile

Author: koenpunt

Example/package.json

@@ -9,7 +9,7 @@
  "dependencies": {
  "react": "16.0.0",
  "react-native": "0.50.3",
- "react-native-admob": "file:../"
+ "react-native-admob": "file:.."
  },
  "devDependencies": {
  "babel-jest": "21.2.0",

Example/yarn.lock

@@ -3311,7 +3311,7 @@ react-devtools-core@^2.5.0:
  shell-quote "^1.6.1"
  ws "^2.0.3"
 
-"react-native-admob@file:../":
+"react-native-admob@file:..":
  version "2.0.0-beta.2"
  dependencies:
  prop-types "^15.5.10"