Convert request spec to minitest
user
```ruby
# frozen_string_literal: true

require "test_helper"
require "judoscale/request"
require "judoscale/config"

module Judoscale
  describe Request do
    let(:request) { Request.new(env, config) }
    let(:env) { {} }
    let(:config) { Config.instance }

    describe "#queue_time" do
      it "handles X_REQUEST_START in integer milliseconds (Heroku)" do
        started_at = Time.now - 2
        ended_at = started_at + 1
        env["HTTP_X_REQUEST_START"] = (started_at.to_f * 1000).to_i.to_s

        _(request.queue_time(ended_at)).must_be_within_delta 1000, 1
      end

      it "handles X_REQUEST_START in seconds with fractional milliseconds (nginx)" do
        started_at = Time.now - 2
        ended_at = started_at + 1
        env["HTTP_X_REQUEST_START"] = "t=#{format "%.3f", started_at.to_f}"

        _(request.queue_time(ended_at)).must_be_within_delta 1000, 1
      end
    end
  end
end
```
assistant