temporarily create files for pages chroot

from: gitlab-org/gitlab-pages#86 (closed)

the following files have to be created on the servers serving pages until that issue is solved:

• /var/opt/gitlab/gitlab-rails/shared/pages/etc/resolv.conf as a copy of /etc/resolv.conf
• /var/opt/gitlab/gitlag-rails/shared/pages/etc/ssl/certs/cacerts.pem as a sum of all the pem files under /etc/ssl/certs/