Ruby 2.7.x & 3 Compatibility release

• Tests work with Ruby 2.6.6, 2.7.2 and 3.0.0$
• Update awsome_print.gemspec nokogiri dependency to resolve CVEs [@gvwirth]

Minor release

No functional changes, just some behind-the-scenes updates:

• Updated code so it can be released to rubygems.
• Updated nokogiri to resolve vulnerability scan

Big bugs fixed; build tests updated; dropped support for ruby < 2.4

There are a number of changes, so please report any bugs you find!

Changes

• Expanded tests to run against Ruby 2.7.x, Rails 6.0-6.1 and Mongoid 7.0-7.1 [@BryanH]
• Update method signature after change in IRB [@febeling]
• Fixes block and proc definition to work with Ruby 3.0.0 [@csalvato] - [#392]
• Removed check for Ruby 2.4 and earlier [@BryanH]
• Rails 5.0 builds are failing, because the sqlite3 version being installed is wrong version [#366]
• Fixes spec suite to properly work via travis, gets a clean build [@imajes, others]
• Adds support for ActiveModel::Errors [@dshinzie] - [#301]
• removes use of strip_heredoc from specs as it's a rails dep [@kstephens] - [#303]
• ArrayFormatter now returns arrays for has_many :through associations [@Chadh13] - [#332]