Use RuboCop RSpec 2.22

This PR uses RuboCop RSpec 2.22 and suppresses the following warning:

```console
$ bundle exec rake
(snip)

Running RuboCop...
.rubocop.yml: RSpec/FactoryBot/CreateList has the wrong namespace - should be FactoryBot
```

Author: koic

.rubocop.yml

@@ -142,10 +142,6 @@ RSpec:
       - expect_offense
       - expect_offense_if_model_file
 
-# This disabling is a workaround for https://github.com/rubocop-hq/rubocop-rails/issues/374.
-RSpec/FactoryBot/CreateList:
-  Enabled: false
-
 RSpec/PredicateMatcher:
   EnforcedStyle: explicit
 

Gemfile

@@ -11,7 +11,7 @@ gem 'rake'
 gem 'rspec'
 gem 'rubocop', github: 'rubocop/rubocop'
 gem 'rubocop-performance', '~> 1.17.0'
-gem 'rubocop-rspec', '~> 2.20.0'
+gem 'rubocop-rspec', '~> 2.22.0'
 gem 'simplecov'
 gem 'test-queue'
 gem 'yard', '~> 0.9'