github-check: add a test for requests from old reviewdog CLI

doghouse/server/doghouse_test.go

@@ -145,6 +145,11 @@ func TestCheck_OK(t *testing.T) {
 					},
 				},
 			},
+			{
+				Path:    "sample.new.txt",
+				Line:    2,
+				Message: "request from old clients",
+			},
 		},
 		Level: "warning",
 	}
@@ -219,6 +224,14 @@ func TestCheck_OK(t *testing.T) {
 					Message:         github.String("test severity override"),
 					Title:           github.String("[haya14busa-linter] sample.new.txt#L2"),
 				},
+				{
+					Path:            github.String("sample.new.txt"),
+					StartLine:       github.Int(2),
+					EndLine:         github.Int(2),
+					AnnotationLevel: github.String("warning"),
+					Message:         github.String("request from old clients"),
+					Title:           github.String("[haya14busa-linter] sample.new.txt#L2"),
+				},
 			}
 			if d := cmp.Diff(annotations, wantAnnotations); d != "" {
 				t.Errorf("Annotation diff found:\n%s", d)