Adding service_identity module to pip_requirements

Change-Id: Ic75db10107e18e4f4287f2fcd68d2d2595d2e506
diff --git a/containers/xos/pip_requirements.txt b/containers/xos/pip_requirements.txt
index 4de76c6..e7a9181 100644
--- a/containers/xos/pip_requirements.txt
+++ b/containers/xos/pip_requirements.txt
@@ -135,6 +135,7 @@
 retrying==1.3.3
 rfc3986==0.4.1
 rsa==3.4.2
+service-identity==17.0.0
 shade==1.9.0
 simplejson==3.8.2
 six==1.10.0