Add existing user logic

There may be a need to run these tests with an existing user.  This
checks the existing user flags and uses that information if they
are true. Defautls to false.

Change-Id: I5dfab4cfa2c55fd133ab7ad2d5235399865794ab
diff --git a/keystone_tempest_plugin/config.py b/keystone_tempest_plugin/config.py
index ae93471..b040fea 100644
--- a/keystone_tempest_plugin/config.py
+++ b/keystone_tempest_plugin/config.py
@@ -44,7 +44,8 @@
     cfg.StrOpt('idp_username',
                help='Username used to login in the Identity Provider'),
     cfg.StrOpt('idp_password',
-               help='Password used to login in the Identity Provider'),
+               help='Password used to login in the Identity Provider',
+               secret=True),
     cfg.StrOpt('idp_ecp_url',
                help='Identity Provider SAML2/ECP URL'),
     cfg.StrOpt('idp_oidc_url',
@@ -56,6 +57,13 @@
     cfg.StrOpt('idp_client_secret',
                help='Identity Provider Client Secret'),
 
+    # existing user (oidc)
+    cfg.StrOpt('idp_test_user_name',
+               help='Identity Provider Test User Name'),
+    cfg.StrOpt('idp_test_user_password',
+               help='Identity Provider Test User Password',
+               secret=True),
+
     # Mapping rules
     cfg.StrOpt('mapping_remote_type',
                help='The assertion attribute to be used in the remote rules'),
@@ -81,5 +89,4 @@
     cfg.StrOpt('protocol_id',
                default='mapped',
                help='The Protocol ID'),
-
 ]