Gemfile in u-attributes-2.0.1 vs Gemfile in u-attributes-2.1.0

@@ -1,7 +1,9 @@
 source 'https://rubygems.org'
 
+gem 'u-case', '~> 4.0'
+
 activemodel_version = ENV.fetch('ACTIVEMODEL_VERSION', '6.1')
 
 activemodel = case activemodel_version
               when '3.2' then '3.2.22'
               when '4.0' then '4.0.13'
@@ -16,12 +18,19 @@
 if activemodel_version < '6.1'
   gem 'activemodel', activemodel, require: false
   gem 'activesupport', activemodel, require: false
 end
 
+simplecov_version =
+  case RUBY_VERSION
+  when /\A2.[23]/ then '~> 0.17.1'
+  when /\A2.4/ then '~> 0.18.5'
+  else '~> 0.19'
+  end
+
 group :test do
   gem 'minitest', activemodel_version < '4.1' ? '~> 4.2' : '~> 5.0'
-  gem 'simplecov', require: false
+  gem 'simplecov', simplecov_version, require: false
 end
 
 # Specify your gem's dependencies in u-attributes.gemspec
 gemspec