David Supplee

chore: introduce functions samples

1

Based on https://github.com/googleapis/gapic-generator-php/pull/483 as a way to check out a service involving the upcoming samples.

When possible, references to protobuf messages should be rendered as links to the generated class

3

For more context: https://github.com/GoogleCloudPlatform/google-cloud-php/pull/1113#discussion_r198255098

Ensure restOptions get passed through to calls to manage auth tokens as well as to the service

3

For more context: https://github.com/GoogleCloudPlatform/google-cloud-php/issues/1202#issuecomment-412566973