Add basic read only glance cli tests

* Display help
* List images

Change-Id: Iee5a4ebf4a47e8c41545c0d404cc15eb345705da
diff --git a/cli/__init__.py b/cli/__init__.py
index 6ffe229..2a00ecc 100644
--- a/cli/__init__.py
+++ b/cli/__init__.py
@@ -70,6 +70,11 @@
         return self.cmd_with_auth(
             'keystone', action, flags, params, admin, fail_ok)
 
+    def glance(self, action, flags='', params='', admin=True, fail_ok=False):
+        """Executes glance command for the given action."""
+        return self.cmd_with_auth(
+            'glance', action, flags, params, admin, fail_ok)
+
     def cmd_with_auth(self, cmd, action, flags='', params='',
                       admin=True, fail_ok=False):
         """Executes given command with auth attributes appended."""