HSEARCH-3051 Add more AWS Elasticsearch environments in the Jenkinsfile

Note we don't test all these environments: they are only taken
into account if CI is configured to provide the URL and credentials
for that particular version.

Jenkinsfile

@@ -190,7 +190,9 @@ stage('Configure') {
 			esAws: [
 					new EsAwsITEnvironment(version: '5.6', mavenProfile: 'elasticsearch-5.6', status: ITEnvironmentStatus.EXPERIMENTAL),
 					new EsAwsITEnvironment(version: '6.0', mavenProfile: 'elasticsearch-6.0', status: ITEnvironmentStatus.EXPERIMENTAL),
-					new EsAwsITEnvironment(version: '6.2', mavenProfile: 'elasticsearch-6.0', status: ITEnvironmentStatus.EXPERIMENTAL)
+					new EsAwsITEnvironment(version: '6.2', mavenProfile: 'elasticsearch-6.0', status: ITEnvironmentStatus.EXPERIMENTAL),
+					new EsAwsITEnvironment(version: '6.3', mavenProfile: 'elasticsearch-6.0', status: ITEnvironmentStatus.EXPERIMENTAL),
+					new EsAwsITEnvironment(version: '6.4', mavenProfile: 'elasticsearch-6.0', status: ITEnvironmentStatus.EXPERIMENTAL)
 			]
 	])