Remove "Starting an elasticsearch container" message in constructor

[deejgregor]

At this point in the constructor, we are not actually starting Elasticsearch, so this message can lead to confusion (it did for me, leading me to dig into it). I didn't find any of the other org.testcontainers container classes that output a message like this in their constructor.

When the container is actually started, we still get a log message from GenericContainer, anyway, so I think we can just safely delete this log line, which is what this PR does.

Notice line 8 where we have Starting an elasticsearch container:

...
20:37:40.568 [main] INFO  🐳 [testcontainers/ryuk:0.3.4] - Creating container for image: testcontainers/ryuk:0.3.4
20:37:41.040 [main] INFO  org.testcontainers.utility.RegistryAuthLocator - Credential helper/store (docker-credential-desktop) does not have credentials for https://index.docker.io/v1/
20:37:49.798 [main] INFO  🐳 [testcontainers/ryuk:0.3.4] - Container testcontainers/ryuk:0.3.4 is starting: 7201de8310b1f5870622b4070203ccf609a9a6a550ab3bfb682193c9f1fe7424
20:38:08.714 [main] INFO  🐳 [testcontainers/ryuk:0.3.4] - Container testcontainers/ryuk:0.3.4 started in PT28.516627S
20:38:08.729 [main] INFO  org.testcontainers.utility.RyukResourceReaper - Ryuk started - will monitor and terminate Testcontainers containers on JVM exit
20:38:08.730 [main] INFO  org.testcontainers.DockerClientFactory - Checking the system...
20:38:08.732 [main] INFO  org.testcontainers.DockerClientFactory - ✔︎ Docker server version should be at least 1.6.0
20:38:08.732 [main] INFO  🐳 [docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2] - Starting an elasticsearch container using [docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2]
20:38:08.824 [main] INFO  🐳 [postgres:10.7-alpine] - Creating container for image: postgres:10.7-alpine
20:38:12.712 [main] INFO  🐳 [postgres:10.7-alpine] - Container postgres:10.7-alpine is starting: f1a9cd20285eea9cc684b76a44916a35e5c9715e787773895f49c164b1a1baa2
20:38:43.861 [main] INFO  🐳 [postgres:10.7-alpine] - Container postgres:10.7-alpine started in PT35.03724S
20:38:44.015 [main] INFO  🐳 [horizon:latest] - Creating container for image: horizon:latest
20:39:44.261 [main] INFO  🐳 [horizon:latest] - Container horizon:latest is starting: 73913f424c20e78c297033c9674286f9659ea87ce124ee08e2c29a9e7cb49a9f
20:39:55.601 [main] INFO  org.opennms.smoketest.containers.OpenNMSContainer - Waiting for startup to begin.
...

I can confirm that no Elasticsearch container has been created f I look at recently-created containers while the test is running. I don't see Elasticsearch, but I do see the other containers listed in the output above (and that I expect to see in this case): ryuk, postgres, and OpenNMS horizon.

CONTAINER ID   IMAGE                                 COMMAND                  CREATED
73913f424c20   horizon:latest                        "/entrypoint.sh -s"      6 minutes ago
f1a9cd20285e   postgres:10.7-alpine                  "docker-entrypoint.s…"   8 minutes ago
7201de8310b1   testcontainers/ryuk:0.3.4             "/app"                   8 minutes ago

In our case, this happens because of the log message in the ElasticsearchContainer constructor, and also our smoke test OpenNMSStack infrastructure that pre-defines a number of container stacks that we use in tests, one of which called ALEC includes Elasticsearch (code). However in the test output I showed above, it wasn't the ALEC stack that was being used--an ElasticsearchContainer object was instantiated, but the container was never actually created or started in this case.

[eddumelendez]

Thanks @deejgregor ! this is now merged in main branch.