Updating samples to new API programming model (GoogleApiClient).
Upgrading samples to new API programming model (GoogleApiClient).
Update README.md
Merge branch 'master' of https://github.com/playgameservices/android-samples

# By Bruno Oliveira
# Via Bruno Oliveira
* 'master' of https://github.com/playgameservices/android-samples:
  Update README.md
  Upgrading samples to new API programming model (GoogleApiClient).
  Updating samples to new API programming model (GoogleApiClient).