* master: (189 commits)
  Update CHANGELOG for !4659
  Center the header logo for all Devise emails
  Add previews for all customized Devise emails
  Customize the Devise `unlock_instructions` email
  Customize the Devise `reset_password_instructions` email
  Customize the Devise `password_change` emails
  Use gitlab-git 10.2.0
  Use Git cached counters on project show page
  Fix indentation scss-lint errors
  Added title attribute to enties in tree view Closes #18353
  Banzai::Filter::ExternalLinkFilter use XPath
  Reduce queries in IssueReferenceFilter
  Use gitlab_git 10.1.4
  Fixed ordering in Project.find_with_namespace
  Fix images in emails
  Banzai::Filter::UploadLinkFilter use XPath
  Turn Group#owners into a has_many association
  Make project_id nullable
  ...