[ISSUE apache#3654] Polish travis.yml to run integration tests (apache#3655)

* 1.Make travis to run integration tests
2.Fix running testSynSendNullMessage failed

* Remove run 'mvn clean install -Pit-test' after success

* Change package to install when running UT

Author: RongtongJin

.travis.yml

@@ -47,9 +47,9 @@ before_script:
 script:
   - mvn verify -DskipTests
   - travis_retry mvn -B clean apache-rat:check
-  - travis_retry mvn -B package jacoco:report coveralls:report
+  - travis_retry mvn -B install jacoco:report coveralls:report
+  - travis_retry mvn -B clean install -pl test -Pit-test
 
 after_success:
-  - mvn clean install -Pit-test
   - mvn sonar:sonar -Psonar-apache
   - bash <(curl -s https://codecov.io/bash) || echo 'Codecov failed to upload'

test/src/test/java/org/apache/rocketmq/test/client/producer/exception/msg/MessageExceptionIT.java

@@ -59,7 +59,7 @@ public void testProducerSmoke() {
         assertThat(sendResult.getSendStatus()).isEqualTo(SendStatus.SEND_OK);
     }
 
-    @Test(expected = org.apache.rocketmq.client.exception.MQClientException.class)
+    @Test(expected = java.lang.NullPointerException.class)
     public void testSynSendNullMessage() throws Exception {
         producer.send((Message) null);
     }