Prior to this commit, the `Gemfile.lock` enforced the use of
Bundler v1.17.3 which was released in 2014.
On Ruby 3, this triggers the following deprecation warning:
```
/home/user/.rvm/gems/ruby-3.0.2@shoulda-matchers/gems/bundler-1.17.3/lib/bundler/shared_helpers.rb:118: warning: Pathname#untaint is deprecated and will be removed in Ruby 3.2.
```
Since the gem itself in v5.0.0 requires at least Ruby v2.6,
it seems fair to require a recent version of Bundler v2,
which in turn runs of every Ruby v2.3 or later.
* Add Appraisal for Rails 6.1
* Upgrade Rails
* fix: standardize error message of association matcher
* Bump listen version to v3.5.1
* Fix the wrong number of arguments (given 2, expected 1)
* Remove deprecated method
* Update Rails to 6.1.3.2
* Remove test for ActiveModel::Errors#generate_message
* Missing ':through' option for has_many association.
* Fix the actual_foreign_key method that is returning a string instead of an array of foreign keys
* Fix Bundler::GemNotFound: Could not find gem 'puma (~> 5.0)'
* Fix Bundler::GemNotFound: Could not find gem 'rack-mini-profiler (~> 2.0)'
* Bump rspec-rails to 4.1.2
* Fix 'rails generate' not working with Rails 6.1
Leo Arnold