Move live migration tests out of scenario job

'tempest-scenario-multinode-lvm-multibackend' job used to run
- all scenario test including slow tests with lvm multi-backend setup
- live migration and migration tests

This commit make scenario job only run the scenario tests and exclude
migration and live migration tests out of it.

coverage of those tests are there in below jobs
- migration tests run as part of -  'neutron-tempest-multinode-full'
- live migration tests run as part of - 'nova-live-migration'

This helps to provide a generic job to run the scenario tests in parallel
including slow tests so that project like nova, cinder, neutron etc can
use this job ti run on their main pipeline.

- http://lists.openstack.org/pipermail/openstack-dev/2018-May/130418.html

Change-Id: Ibddd633a3fdccb11100f5bc150c4595147402237

.zuul.yaml

@@ -146,6 +146,9 @@
 - job:
     name: tempest-scenario-multinode-lvm-multibackend
     parent: legacy-dsvm-base-multinode
+    description: |
+      This job will run all scenario tests including slow tests
+      with lvm multibackend setup.
     run: playbooks/tempest-scenario-multinode-lvm-multibackend/run.yaml
     post-run: playbooks/tempest-scenario-multinode-lvm-multibackend/post.yaml
     timeout: 10800

playbooks/tempest-scenario-multinode-lvm-multibackend/run.yaml

@@ -47,8 +47,8 @@
           set -x
           export PYTHONUNBUFFERED=true
           export DEVSTACK_GATE_TEMPEST=1
-          # Run scenario and nova migration tests with concurrency 2
-          export DEVSTACK_GATE_TEMPEST_REGEX='(^tempest\.(scenario|api\.compute\.admin\.test_(live_|)migration))'
+          # Run all scenario tests including slow tests with concurrency 2
+          export DEVSTACK_GATE_TEMPEST_REGEX='(^tempest\.(scenario))'
           export TEMPEST_CONCURRENCY=2
           export DEVSTACK_GATE_NEUTRON=1
           export DEVSTACK_GATE_TLSPROXY=1