Kewpie random test generation

This blueprint describes how automatic test generation will be handled by kewpie.

Recently xtrabackup_manager library was added into kewpie, which allows to create backup objects from server objects. From code it looks like a single "command" (actually method call).

Idea of test generation relies on a good set of methods, and test generation itself is a generation of methods' sequence to form a test scenario and run it.