message: Move test dashboard link in README
diff: Minigo: A minimalist Go engine modeled after AlphaGo Zero, built on MuGo
  ==================================================
  -[Test Dashboard](https://k8s-testgrid.appspot.com/sig-big-data#tf-minigo-presubmit)
  -
  This is a pure Python implementation of a neural-network based Go AI, using
  TensorFlow. While inspired by DeepMind's AlphaGo algorithm, this project is not
  a DeepMind project nor is it affiliated with the official AlphaGo project.
  @@ -120,6 +118,8 @@ Running unit tests
  Automated Tests
  ----------------
  +[Test Dashboard](https://k8s-testgrid.appspot.com/sig-big-data#tf-minigo-presubmit)
  +
  To automatically test PRs, Minigo uses
  [Prow](https://github.com/kubernetes/test-infra/tree/master/prow), which is a
  test framework created by the Kubernetes team for testing changes in a hermetic
  