Add new gate for multinode

Change-Id: I3e05e2d5c739794ae6ff0cc375dc6226f81bb542
Paritially-Implements: blueprint multinode-gate

tox.ini

@@ -95,6 +95,15 @@ commands =
    bash tests/setup_deploy.sh
    sudo tests/deploy_aio.sh ubuntu source
 
+[testenv:deploy-multinode-images-ubuntu-source]
+whitelist_externals = find
+                      bash
+                      sudo
+commands =
+   find . -type f -name "*.pyc" -delete
+   bash -c "if [ ! -d .testrepository ]; then testr init; fi"
+   sudo -g docker testr run test_build.BuildTestUbuntuSource
+
 [testenv:functional]
 whitelist_externals = find
                       bash