Add Elasticsearch

[abaniuszewicz]

Added Serilog sink that will log to Elasticsearch. Logs are accessible via Kibana.

How to test:

1. Build & launch.
2. Make some dummy requests to the API, for example you can fetch http://localhost:5000/api/v1/teams couple of times.
3. Go to http://localhost:5601 where you should see Kibana dashboard. On the left menu, in the "Analytics" section, click on the "Discover" item.
4. Click on "Create data view" button. Enter devup as a name and devup-logs-* as the index pattern and click on "Save data view to Kibana".
5. You should be able to see logs from the requests that you executed on step 2. If you'll make new requests to the API now, they should appear there as well.

If needed, Elasticsearch can be accessed at http://localhost:9200. You can see its stats on http://localhost:9200/_stats.