bind some integration jobs

On master, should be on 'gallium' but the slave uses a different
username 'jenkins-slave':

- integration-docroot-deploy

On 'gallium' since we need a Zuul install:

- integration-zuul-layoutdiff
- integration-zuul-layoutvalidation

Change-Id: Ie12a84732b5da84c5f6abaca9284b97473235a9a