* master: (131 commits)
  Use Ruby 2.7.1
  Trigger actions on pull requests to master
  Bump Rake to v13
  Bump rake to v13
  Use flat_map instead of map.flatten in defaults
  Reduce memory usage in compute
  Reduce memory usage in Tag::Parents module
  Map in-place subtags
  Use flat_map instead of map.flatten in normalize_key
  Double-splat the arguments for I18n.translate
  Revert "Fix Ruby 2.7 keyword arguments related deprecation warning in Proc call"
  Misc readme updates
  Added double splat to resolve deprecation warning
  Switch to new GitHub issue template
  Update issue templates
  Bump to 1.8.2
  Fix regression introduced by b7f69f7
  Add pry to Gemfile
  Expand post-install message to clarify for new apps
  Revert "Revert "Chain fallback backends""
  ...