Add a testcase with a binlog postion of >1 byte

Author: dveeden

replication/event_test.go

@@ -234,6 +234,12 @@ func TestHeartbeatEvent(t *testing.T) {
 			[]byte{},
 			HeartbeatEvent{},
 		},
+		{
+			false,
+			2,
+			[]byte{0x1, 0xd, 0x62, 0x69, 0x6e, 0x6c, 0x6f, 0x67, 0x2e, 0x30, 0x30, 0x30, 0x30, 0x30, 0x31, 0x2, 0x4, 0xfd, 0xbb, 0xaf, 0x27, 0x0},
+			HeartbeatEvent{Version: 2, Filename: "binlog.000001", Offset: 2600891},
+		},
 	}
 
 	for _, tc := range testcases {