Fix the error where the cluster memeber cannot be started in tests.

The cluster memeber shutdown requires proper stop call rather than kill to ensure the databases are closed properly in 4.0.
Also the status check shall not assume a LEADER is always presented in the cluster.

Author: Zhen Li

driver/src/test/java/org/neo4j/driver/v1/integration/CausalClusteringIT.java

@@ -386,7 +386,7 @@ void shouldNotServeWritesWhenMajorityOfCoresAreDead()
             Set<ClusterMember> cores = cluster.cores();
             for ( ClusterMember follower : cluster.followers() )
             {
-                cluster.kill( follower );
+                cluster.stop( follower );
             }
             awaitLeaderToStepDown( cores );
 
@@ -428,7 +428,7 @@ void shouldServeReadsWhenMajorityOfCoresAreDead()
             Set<ClusterMember> cores = cluster.cores();
             for ( ClusterMember follower : cluster.followers() )
             {
-                cluster.kill( follower );
+                cluster.stop( follower );
             }
             awaitLeaderToStepDown( cores );
 

driver/src/test/java/org/neo4j/driver/v1/integration/CredentialsIT.java

@@ -26,6 +26,8 @@
 import java.util.Map;
 
 import org.neo4j.driver.internal.security.InternalAuthToken;
+import org.neo4j.driver.internal.util.DisabledOnNeo4jWith;
+import org.neo4j.driver.internal.util.Neo4jFeature;
 import org.neo4j.driver.v1.AuthToken;
 import org.neo4j.driver.v1.AuthTokens;
 import org.neo4j.driver.v1.Config;
@@ -58,6 +60,8 @@ class CredentialsIT
     static final DatabaseExtension neo4j = new DatabaseExtension();
 
     @Test
+    @DisabledOnNeo4jWith( Neo4jFeature.BOLT_V4 )
+    // This feature is removed in 4.0
     void shouldBePossibleToChangePassword() throws Exception
     {
         String newPassword = "secret";

driver/src/test/java/org/neo4j/driver/v1/util/cc/Cluster.java

@@ -273,11 +273,7 @@ private static void waitForMembersToBeOnline( Set<ClusterMember> members, Cluste
             try
             {
                 final Map<BoltServerAddress,ClusterMemberRole> clusterOverview = discovery.findClusterOverview( driver );
-                // we will wait until the leader is online
-                if ( clusterOverview.containsValue( ClusterMemberRole.LEADER ) )
-                {
-                    actualOnlineAddresses = clusterOverview.keySet();
-                }
+                actualOnlineAddresses = clusterOverview.keySet();
             }
             catch ( Throwable t )
             {