Destructive test for neutron l3 agent

Pacemaker should restart neutron l3 agent
Scenario:
1. Deploy Ha with neutron
2. Pick up host where l3 agent is running
3. Turn off host
4. Wait some time
6. Create several vms to be sure that vms receive ip addresses
(Performed by OSTF connectivity tests)

Partially fix bug: https://bugs.launchpad.net/fuel/+bug/1269806
Implements first scenario

Related-bug: #1269806
Change-Id: I30d06753b72842e0db03f96914029f5d2dec8502
Merge "Destructive test for neutron l3 agent"