message: Update clone link in CONTRIBUTING.md
diff: @@ -23,7 +23,7 @@ The core team will be monitoring for pull requests. When we get one, we'll run s
  1. Fork the repo and create your branch from `master`.
  ```sh
  - git clone https://github.com/facebook/jest
  + git clone https://github.com/<your_username>/jest
  cd jest
  git checkout -b my_branch
  ```
  