Fuel kick-start file should be tuned for CentOS 7 default settings

[Albert Syriy]

Fuel kick-start file should be modified when migrating to CentOS 7.
There are two concerns (potential issues):
1. Systemd, which is using for control services in CentOS 7, doesn't call the rc.local script by default. The systemd rc-local.service should be enabled.
2. Ethernet network interfaces are disabled by default. Parameter "ONBOOT=no" should be changed to "ONBOOT=yes" in the configuration file /etc/sysconfig/network/ifcfg-<interface>.

See the link for details:
https://wiki.centos.org/FAQ/CentOS7

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/237441

[OpenStack Infra (hudson-openstack)]

Change abandoned by Albert Syriy (<email address hidden>) on branch: master
Review: https://review.openstack.org/237441
Reason: It doesn't have sense to enable interfaces by default, let a user do it.

[Albert Syriy (asyriy)]

The two potential issues are not issues.
1. The systemd calls rc-local.service by default , which invokes in its turn rc.loacal file when it has rights for execution.
Since the rc.local is formed during installation and has execution rights, no additional efforts required.
2. Ethernet network interfaces are disabled by default. But lets a user enable required interfaces explicitly. It's not an issue too.