DATAREDIS-576 - Polishing.

Update Javadoc, apply missing @Nullable annotations, add tests and alter makefile to use Redis 4.0.2.

Original Pull Request: #285

src/test/java/org/springframework/data/redis/connection/lettuce/LettuceClientConfigurationUnitTests.java

@@ -73,4 +73,14 @@ public class LettuceClientConfigurationUnitTests {
 		assertThat(configuration.getCommandTimeout()).isEqualTo(Duration.ofMinutes(5));
 		assertThat(configuration.getShutdownTimeout()).isEqualTo(Duration.ofHours(2));
 	}
+
+	@Test(expected = IllegalArgumentException.class) // DATAREDIS-576
+	public void clientConfigurationThrowsExceptionForNullClientName() {
+		LettuceClientConfiguration.builder().clientName(null);
+	}
+
+	@Test(expected = IllegalArgumentException.class) // DATAREDIS-576
+	public void clientConfigurationThrowsExceptionForEmptyClientName() {
+		LettuceClientConfiguration.builder().clientName(" ");
+	}
 }

src/test/java/org/springframework/data/redis/connection/lettuce/LettuceConnectionFactoryTests.java

@@ -372,12 +372,12 @@ public class LettuceConnectionFactoryTests {
 		factory.setShareNativeConnection(false);
 		factory.afterPropertiesSet();
 
+		ConnectionFactoryTracker.add(factory);
+
 		RedisConnection connection = factory.getConnection();
 
 		assertThat(connection.getClientName(), is(equalTo("clientName")));
 		connection.close();
-
-		factory.destroy();
 	}
 
 	@Test // DATAREDIS-576
@@ -388,11 +388,11 @@ public class LettuceConnectionFactoryTests {
 		factory.setClientName("clientName");
 		factory.afterPropertiesSet();
 
+		ConnectionFactoryTracker.add(factory);
+
 		RedisConnection connection = factory.getConnection();
 		assertThat(connection.getClientName(), equalTo("clientName"));
 
 		connection.close();
-
-		factory.destroy();
 	}
 }