Improve exit code for errors in 'puppetserver ca list'

Use case: I'm working on some scripting to run a puppetserver ca command.  I want to put in a safeguard to prevent someone from running a CA command on a compile master.  The notion I had was to detect the ca-master by looking at the CA.

A CA master runs puppetserver ca list --all just like you would expect.  On the compile masters, though:

# puppetserver ca list --all

Error:

 code: 403

 body: Forbidden request: /puppet-ca/v1/certificate_statuses/any_key (method :get). Please see the server logs for details.

No certificates to list

# echo $?

0

Since everything about that query was a failure, I would expect an error code to be returned.  Instead the error is all in the text.  While obvious to a human that this failed, with it having exited 0 we're into grepping text to find that the command failed.