cloudius-systems/capstan — pull request #108 by asias (2014-06-03 07:37:39+00:00)
Title: gce: Check if user logins with GCE

It's easy for new user to forget to login with GCE before running
capstan + GCE. Do a check and prompt friendly.

If you do not login with GCE, it will prompt:

You do not currently have an active account selected.
Please run:

$ gcloud auth login

to obtain new credentials, or if you have already logged in with a
different account:

$ gcloud config set account

to select an already authenticated account to use.

Signed-off-by: Asias He