Add minitest to gemspec

Author: marcoroth

Gemfile.lock

@@ -215,6 +215,7 @@ PLATFORMS
 DEPENDENCIES
   bundler (~> 2.0)
   magic_frozen_string_literal (~> 1.2)
+  minitest (= 5.18.1)
   mocha (~> 1.13)
   rails (>= 5.2, < 8)
   rake (~> 13.0)

stimulus_reflex.gemspec

@@ -58,4 +58,5 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency "rails", *rails_version
   gem.add_development_dependency "rake", "~> 13.0"
   gem.add_development_dependency "standard", "~> 1.24"
+  gem.add_development_dependency "minitest", "5.18.1"
 end