Integration tests run in multi-region

Summary
=======
Integration tests run in a multi-region openstack deployment

Motivation
========
Integration testing on Multi-region

Description
=========
Multi-region test will be executed on local environment at first

UX
===
N/A.

Wireframes, Mocks, Videos and UI Markup
---------------------------------------------------------
N/A.

Testing
======
Testing step:
1: .devstack config with region
deploy two OpenStack in different regions with shared keystone service which is installed in region one

[[local|localrc]]
REGION_NAME=RegionOne
OFFLINE=False
GIT_BASE=https://github.com
HOST_IP=localhost
LOGDAYS=1
LOGFILE=$DEST/logs/stack.sh.log
SCREEN_LOGDIR=$DEST/logs/screen
VERBOSE=TRUE
DATABASE_PASSWORD=password
ADMIN_PASSWORD=password
SERVICE_PASSWORD=password
SERVICE_TOKEN=password
RABBIT_PASSWORD=password
KEYSTONE_TOKEN_FORMAT=uuid
RECLONE=yes
IMAGE_URLS+=",http://cdn.download.cirros-cloud.net/0.3.2/cirros-0.3.2-x86_64-disk.img"
IMAGE_URLS+=",http://sahara-files.mirantis.com/sahara-icehouse-vanilla-1.2.1-ubuntu-13.10.qcow2"
IMAGE_URLS+=",http://cloud.fedoraproject.org/fedora-20.x86_64.qcow2"
ENABLED_SERVICES=rabbit,mysql,key
ENABLED_SERVICES+=,n-api,n-crt,n-obj,n-cpu,n-cond,n-sch,n-novnc,n-cauth
ENABLED_SERVICES+=,neutron,q-svc,q-agt,q-dhcp,q-l3,q-meta
ENABLED_SERVICES+=,s-proxy,s-object,s-container,s-account
ENABLED_SERVICES+=,g-api,g-reg
ENABLED_SERVICES+=,cinder,c-api,c-vol,c-sch,c-bak
SWIFT_HASH=66a3d6b56c1f479c8b4e70ab5c2000f5
SWIFT_LOOPBACK_DISK_SIZE=4G
ENABLED_SERVICES+=,horizon
ENABLED_SERVICES+=,sahara
KEYSTONE_TOKEN_FORMAT=PKI
Q_USE_DEBUG_COMMAND=True
Q_USE_SECGROUP=True
enable_service ceilometer-acompute ceilometer-acentral ceilometer-anotification ceilometer-collector
enable_service ceilometer-alarm-evaluator,ceilometer-alarm-notifier
enable_service ceilometer-api
CEILOMETER_BACKEND=mongo
enable_service heat h-api h-api-cfn h-api-cw h-eng

2: local_settings.py
AVAILABLE_REGIONS = [
     ('http://devstack:5000/v2.0', 'RegionOne'),
     ('http://devstack:5000/v2.0', 'RegionOne'),
 ]

3: ./run_test.sh --integration

Outside Dependencies
==================
N/A.

Requirements Update Required
========================
N/A.

Doc Impact
=========
horizon.conf