gcloud auth print-access-token transient error

[jrynyt]

Running Command: /google-cloud-sdk/bin/gcloud auth activate-service-account --key-file /tmp/gcloud.json
Activated service account credentials for: [games-drone@nyt-games-prd.iam.gserviceaccount.com]
error creating access token: exit status 1

[info] build failed (exit code 1)

a few retries didn't work, then it did

also note

NAME
    gcloud auth print-access-token - print an access token for the active
        account
...
NOTES
    This command is an internal implementation detail and may change or
    disappear without notice.

see if there's a more official way to get the token, and/or get more info out of the error to understand why it fails, maybe have the plugin retry a few times

[jrynyt]

possibly related: #16, but unclear how that would affect it.