Fix API doc link in Cloud Trace README (#752)
Fix API doc link in Cloud Trace README (#752)


chingor13/google-cloud-php,jdpedrie/google-cloud-php,chingor13/google-cloud-php,jdpedrie/google-cloud-php,jdpedrie/google-cloud-php,chingor13/google-cloud-php,googleapis/google-cloud-php,googleapis/google-cloud-php,googleapis/google-cloud-php