* source/master:
  Update PRY integration section (awesome-print#411)
  BigDecimal required; test fixes for ruby 3 (awesome-print#408)
  Bump canonical (awesome-print#406)
  Ruby 2.6, 2.7 and 3 fixes (awesome-print#405)
  Added canonical for rubygems (awesome-print#401)
  Updated nokogiri to fix vulnerability scan failures (awesome-print#400)
  Corrected bug in examples (issue awesome-print#326); added example headers (awesome-print#398)
  Updated config to remove deprecations (awesome-print#397)
  Update CHANGELOG & fixed travis fails (awesome-print#394)
  Added mongoid 7 gemsets; ignore vendor/bundle (awesome-print#395)
  Added rails 6.0 and 6.1 tests to travis (awesome-print#396)
  Fix method signature after change in IRB (awesome-print#390)
  Fixes block and proc definition to work with Ruby 3.0.0 (awesome-print#392)
  Retire eol rubies (awesome-print#393)
  Use rails 5.2 when testing frozen strings
  Fix frozen string errors
  Run frozen string specs against ruby 2.6
  Run builds against ruby 2.6 instead of head
  Lock rails 5 to correct sqlite3 version

* Added rails 6.0 and 6.1 to travis

* Added rails 6 support files

* Added data for rais 6.x tests

* Rails 6 date helper includes float seconds

* Updated actionview test for rails 6.1

Co-authored-by: Bryan Hanks, PMP <bryan@master-developer.com>