Upgrading sailor to 2.6.1

[kirill-levitskiy]

DoD
Development:

• use new logger
• component should be dockerised, add: "buildType":"docker" line into component.json
• sailor version is changed from 2.3.0 to 2.6.1
• CHANGELOG.md is updated

QA:

• Smoke test is finished
• Regression testing is finished (optional)
• Support is asked to deploy to the production stage (app.elastic.io) and/or another required stage
• Component is actually deployed to the production stage (app.elastic.io) and/or another required stage
• Smoke after deploying to the production stage

Smoke test checklist

• Push to platform
• Retrieve sample
• Retrieve sample on LA (if possible)
• Run keen flow
• Run realtime flow