Elasticsearch requires a test connection to work on startup

[coltoneshaw]

When starting the Mattermost environment for the first time, it defaults to using Elasticsearch since it's configured. However, Elasticsearch will not properly index / run without clicking the test connection button. Once you've pressed this, you have to purge, then reindex the env. With this complete, it starts working.

I'm looking for a solution to trigger this test on startup.