test/cli: specify expected argument values

In the basic invocation test, specify the expected argument values
not only their type. With the exception of the default image type
they correspond to the various command line arguments given.

test/unit/test_cli.py

@@ -77,6 +77,14 @@ class TestCliPlugin(PluginTest):
 
         # check one successful invocation
         argv = ["name", "version", "distro", "target", "arch1"]
+
+        expected_args = ["name", "version", "distro",
+                         ['qcow2'], # the default image type
+                         "target",
+                         ['arch1']]
+
+        expected_opts = {}
+
         task_result = {"compose_id": "42", "build_id": 23}
         task_id = 1
         koji_lib = self.mock_koji_lib()
@@ -87,7 +95,7 @@ class TestCliPlugin(PluginTest):
         self.mock_session_add_valid_tag(session)
 
         session.should_receive("osbuildImage") \
-               .with_args(str, str, str, list, str, list, opts=dict) \
+               .with_args(*expected_args, opts=expected_opts) \
                .and_return(task_id) \
                .once()