README: add recent biqquery changes
README: add recent biqquery changes

Change-Id: Ia0fce68861936107b7e219c2c31490829227a80a
Reviewed-on: https://code-review.googlesource.com/9716
Reviewed-by: Ross Light <dfccc06f14414bff5a59be7fc90abf4404b47fc8@google.com>

googleapis/google-cloud-go,michael-grosshans/google-cloud-go,googleapis/google-cloud-go,michael-grosshans/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go