force shade v1.9.0 as v1.10.0 is broken, using pip

Change-Id: I093bdc020e2237817783e138b2c15b38f3595860
diff --git a/containers/xos/Dockerfile.base b/containers/xos/Dockerfile.base
index 578f417..5a98edb 100644
--- a/containers/xos/Dockerfile.base
+++ b/containers/xos/Dockerfile.base
@@ -75,7 +75,7 @@
 # Required for Ansible 2.x OpenStack os_* modules
 RUN pip install --upgrade pbr && \
     pip install --upgrade six && \
-    pip install shade
+    pip install shade==1.9.0
 
 # Copy over ansible hosts
 COPY ansible-hosts /etc/ansible/hosts