support latest 2nd instance configs

* depends on using bosh-lite-2nd-instance/bin/provision_cf
* adds scripts/configure_offline_bosh.sh to configure second instance as offline
* needs at least this commit of bosh-lite-2nd-instance https://github.com/cf-buildpacks/bosh-lite-2nd-instance/commit/4047b6fce6be883245b766df7cb98a2726edd0e1