Add missing @Test annotation

Author: cowtowncoder

avro/src/test/java/com/fasterxml/jackson/dataformat/avro/EnumTest.java

@@ -151,6 +151,7 @@ public void test_avroSchemaWithString_fromStringValueToEnumValue() throws Except
     }
 
     // [dataformats-binary#388]: Default value for enums with class
+    @Test
     public void testClassEnumWithDefault() throws Exception
     {
         AvroSchemaGenerator gen = new AvroSchemaGenerator();