Enable configuration of Identity API v3

* Default IDENTITY_API_VERSION to '2.0' in stackrc

Note: the value of these *_API_VERSION variables will NOT include
the leading 'v' as the CLI tools do not allow it.

Change-Id: Ic6473833be35625282e7442f3c88fc1c4d0cc134
diff --git a/openrc b/openrc
index f1026a5..1321ce7 100644
--- a/openrc
+++ b/openrc
@@ -75,6 +75,9 @@
 # Set the pointer to our CA certificate chain.  Harmless if TLS is not used.
 export OS_CACERT=$INT_CA_DIR/ca-chain.pem
 
+# Identity API version
+export OS_IDENTITY_API_VERSION=${IDENTITY_API_VERSION:-2.0}
+
 # Currently novaclient needs you to specify the *compute api* version.  This
 # needs to match the config of your catalog returned by Keystone.
 export NOVA_VERSION=${NOVA_VERSION:-1.1}