remote: add test case to show default

tests/func/test_remote.py

@@ -145,6 +145,12 @@ class TestRemoteDefault(TestDvc):
         self.assertEqual(default, None)
 
 
+def test_show_default(dvc_repo, caplog):
+    assert main(["remote", "default", "foo"]) == 0
+    assert main(["remote", "default"]) == 0
+    assert "foo" == caplog.record_tuples[0][2]
+
+
 class TestRemoteShouldHandleUppercaseRemoteName(TestDvc):
     upper_case_remote_name = "UPPERCASEREMOTE"