Fix tests after JUnit 5 upgrade

They were not in main.

Author: acogoluegnes

src/test/java/com/rabbitmq/client/DefaultJsonRpcTest.java

@@ -15,17 +15,17 @@
 
 package com.rabbitmq.client;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
 import com.rabbitmq.tools.jsonrpc.DefaultJsonRpcMapper;
 import com.rabbitmq.tools.jsonrpc.JsonRpcException;
 import com.rabbitmq.tools.jsonrpc.JsonRpcMapper;
-import org.junit.Test;
 
 import java.lang.reflect.UndeclaredThrowableException;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import org.junit.jupiter.api.Test;
 
 public class DefaultJsonRpcTest extends AbstractJsonRpcTest {
 

src/test/java/com/rabbitmq/client/test/ChannelNTest.java

@@ -56,11 +56,12 @@ public void serverBasicCancelForUnknownConsumerDoesNotThrowException() throws Ex
         channel.processAsync(new AMQCommand(method));
     }
 
-    @Test(expected = IOException.class)
+    @Test
     public void callingBasicCancelForUnknownConsumerThrowsException() throws Exception {
         AMQConnection connection = Mockito.mock(AMQConnection.class);
         ChannelN channel = new ChannelN(connection, 1, consumerWorkService);
-        channel.basicCancel("does-not-exist");
+        assertThatThrownBy(() ->  channel.basicCancel("does-not-exist"))
+            .isInstanceOf(IOException.class);
     }
 
     @Test

src/test/java/com/rabbitmq/client/test/JSONReadWriteTest.java

@@ -16,16 +16,17 @@
 
 package com.rabbitmq.client.test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
 import com.rabbitmq.tools.json.JSONReader;
 import com.rabbitmq.tools.json.JSONWriter;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
+import org.junit.jupiter.api.Test;
 
 public class JSONReadWriteTest {
 
-    @Test public void readWriteSimple() throws Exception {
+    @Test
+    public void readWriteSimple() throws Exception {
 
         Object myRet;
         String myJson;