Correct shade keystone v2 job

The clouds.yaml file does not exist until devstack runs, so
we cannot edit it at this point. Instead, set an environment
variable that we can read in the shade post_test_hook script
and use it to modify the clouds.yaml file there.

Change-Id: Ibadf06f5426feabb3f7d198c24c4b5b2ea12eba0

jenkins/jobs/shade.yaml

@@ -13,6 +13,7 @@
       - devstack-checkout
       - shell: |
           #!/bin/bash -xe
+          export SHADE_USE_KEYSTONE_V2=1
           export PYTHONUNBUFFERED=true
           export DEVSTACK_GATE_TIMEOUT=60
           export DEVSTACK_GATE_NEUTRON=1
@@ -26,9 +27,6 @@
               $BASE/new/shade/shade/tests/functional/hooks/post_test_hook.sh
           }}
           export -f post_test_hook
-
-          sed -ie "s/identity_api_version: '3'/identity_api_version: '2.0'/g" ~/.config/openstack/clouds.yaml
-          sed -ie '/^.*domain_id.*$/d' ~/.config/openstack/clouds.yaml
           cp devstack-gate/devstack-vm-gate-wrap.sh ./safe-devstack-vm-gate-wrap.sh
           ./safe-devstack-vm-gate-wrap.sh