Add integration tests for Scenario imports
user
```ruby
require 'rails_helper'

describe ScenarioImportsController do
  let(:user) { users(:bob) }

  before do
    login_as(user)
  end

  it 'renders the import form' do
    visit new_scenario_imports_path
    expect(page).to have_text('Import a Public Scenario')
  end

  it 'requires a URL or file uplaod' do
    visit new_scenario_imports_path
    click_on 'Start Import'
    expect(page).to have_text('Please provide either a Scenario JSON File or a Public Scenario URL.')
  end

  it 'imports a scenario that does not exist yet' do
    visit new_scenario_imports_path
    attach_file('Option 2: Upload a Scenario JSON File', File.join(Rails.root, 'data/default_scenario.json'))
    click_on 'Start Import'
    expect(page).to have_text('This scenario has a few agents to get you started. Feel free to change them or delete them as you see fit!')
    expect(page).not_to have_text('This Scenario already exists in your system.')
    check('I confirm that I want to import these Agents.')
    click_on 'Finish Import'
    expect(page).to have_text('Import successful!')
  end

  it 'asks to accept conflicts when the scenario was modified' do
    DefaultScenarioImporter.seed(user)
    agent = user.agents.where(name: 'Rain Notifier').first
    agent.options['expected_receive_period_in_days'] = 9001
    agent.save!
    visit new_scenario_imports_path
    attach_file('Option 2: Upload a Scenario JSON File', File.join(Rails.root, 'data/default_scenario.json'))
    click_on 'Start Import'
    expect(page).to have_text('This Scenario already exists in your system.')
    expect(page).to have_text('9001')
    check('I confirm that I want to import these Agents.')
    click_on 'Finish Import'
    expect(page).to have_text('Import successful!')
  end
end
```
assistant