* master: (54 commits)
  Updated image for diff navigation docs
  Milestone sidebar docs
  Use app host instead of asset host when rendering image blob or diff
  ActiveRecord::StaleObjectError: Attempted to update a stale object: Ci::Build
  Use shared interceptor in note specs
  Ignore temporary table in schema
  Check for null in job tooltip title
  Clarify casing of I18N placeholder names
  fixes some markup issues in the js style guide docs
  Fix migration that removes issues.branch_name
  small change to make less conflict with EE version
  Add cop for use of remove_column
  Resolve merge conflicts with dev.gitlab.org/master after security release
  add index for doc/administration/operations/
  Remove RubySampler#sample_objects for performance as well
  Bugfix: User can't change the access level of an access requester
  Add spec for removing issues.assignee_id
  updated imports
  Keep track of storage check timings
  Remove a header level in the new 'Automatic CE->EE merge' doc
  ...