[systest] Change default DHCP ranges in tests for multiple cluster networks

[Artem Panchenko]

In 8.0 Fuel is able to automatically configure DHCP server for PXE (slaves discovering) basing on current network configuration (see blueprint dynamic-dnsmasq). So it's possible to change IP addresses ranges for PXE network after master node setup (previously it was possible using fuelmenu during installation only). That's why we need to add new steps to the system tests for multiple cluster networks feature:

- (before nodes bootstrap) create cluster and change IP range for default admin/pxe network, so 10 first addresses are excluded;
- bootstrap slaves from default nodegroup and check that their IPs are from defined range;
- (after cluster deployment) check that nodes' admin IPs are from defined range;

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/248477

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/248477
Committed: https://git.openstack.org/cgit/openstack/fuel-qa/commit/?id=6e855eead1541878a3a35b7380c165c0c1f6519f
Submitter: Jenkins
Branch: master

commit 6e855eead1541878a3a35b7380c165c0c1f6519f
Author: Artem Panchenko <email address hidden>
Date: Sun Nov 22 18:22:13 2015 +0200

    Change admin IP ranges in tests for node groups

    Change default IP addresses range for admin/pxe network
    in system test for multiple cluster networks feature.
    Check that DHCP range is configured properly and Nailgun
    doesn't allocate excluded from range IPs to nodes.

    Change-Id: I64069e287a6970b93931d93212efb0c1712af40a
    Closes-bug: #1513154