test: add test case for v03

Author: sunng87

formats/avro/src/test/java/io/cloudevents/avro/AvroFormatTest.java

@@ -60,4 +60,33 @@ public void testSerde() {
         assertThat(cloudEvent2.getType()).isEqualTo("testdata");
     }
 
+    @Test
+    public void testV03Serde() {
+        EventFormat avroFormat = new AvroFormat();
+        CloudEventData cloudEventData = new AvroCloudEventDataWrapper(testData);
+
+        assertThat(cloudEventData).isNotNull();
+        assertThat(cloudEventData.toBytes()).isNotNull();
+
+        CloudEvent cloudEvent = CloudEventBuilder.v03()
+            .withId("1")
+            .withType("testdata")
+            .withSource(URI.create("http://localhost/test"))
+            .withData("application/avro", cloudEventData)
+            .build();
+        assertThat(cloudEvent).isNotNull();
+        assertThat(cloudEvent.getSpecVersion()).isEqualTo(SpecVersion.V03);
+
+        byte[] bytes = avroFormat.serialize(cloudEvent);
+
+        assertThat(bytes).isNotNull();
+        assertThat(bytes).hasSizeGreaterThan(0);
+
+        CloudEvent cloudEvent2 = avroFormat.deserialize(bytes);
+
+        assertThat(cloudEvent2).isNotNull();
+        assertThat(cloudEvent2.getId()).isEqualTo("1");
+        assertThat(cloudEvent2.getType()).isEqualTo("testdata");
+    }
+
 }