kibana weekly update contains platform migration, security and accessibility enhancements

Kibana's latest updates as of February 2020 highlight improvements in accessibility, security, and platform functionality, aligning with the recent 7.6 release. The team introduced an accessibility statement to demonstrate their commitment to building inclusive user interfaces, while security enhancements include the deprecation of the kibana_user and kibana_dashboard_only_user roles in favor of more specific Kibana Privileges. Additionally, the platform now supports CSS and Sass in plugins through webpack imports, and the validation library @kbn/config-schema can parse arrays and objects from JSON strings, facilitating automatic parsing of various JSON structures. The completion of the Kibana Platform Testing Guide offers examples and tips for testing plugins effectively across unit, integration, and end-to-end scenarios, supporting developers in optimizing their workflows.