* ee/master: (183 commits)
  Improve has_codeclimate_data? spec in the merge_request_spec.rb
  Refactor Elasticsearch checks to SystemCheck
  Refactor and move things around to improve in YAGNI perspective
  Fix BasicExecutor specs
  Changelog
  Fixed and improved some existing checks and SystemCheck library
  Fix codestyle
  Improve Specs and some fixes
  Add ActiveUsers Check
  Refactor gitlab:app:checks to use SystemCheck
  Added specs for BaseExecutor
  Added specs for SystemCheck and custom matcher
  Fix a few method signature checks
  Move rainbow monkey patch to String to spec_helper
  Some code-style fixes and documentation
  WIP SystemCheck library for executing checks from a rake task
  Persist Clone URL prefix in geo_nodes table to be used by the secondary
  Add small improvements to code climate ci docs
  Changelog
  Refactor codeclimate related code for build and pipeline
  ...