Use minitest test task

Rakefile

@@ -1,13 +1,13 @@
 # frozen_string_literal: true
 
 require "bundler/gem_tasks"
-require "rake/testtask"
+require "minitest/test_task"
 require "rubocop/rake_task"
 require "yard"
 
-Rake::TestTask.new do |t|
+Minitest::TestTask.create do |t|
   t.libs << "test"
-  t.pattern = "test/**/*_test.rb"
+  t.test_globs = ["test/**/*_test.rb"]
 end
 RuboCop::RakeTask.new
 YARD::Rake::YardocTask.new