Open SSH tunnel to LogSearch when running from CF

In addition to starting `logsearch-purge-bot.exe`, a SSH tunnel should be started to give the bot container a network path into the logsearch cluster.

the SSH tunnel command will be something like:

`ssh -L 127.0.0.1:9200: elasticsearch.srv-int.logsearch.cityindextest5.co.uk:9200 ubuntu@logsearch.cityindextest5.co.uk`

`elasticSearchUrl` will then need to be set to `127.0.0.1:9200`, which will route over the tunnel to `elasticsearch.srv-int.logsearch.cityindextest5.co.uk:9200`