import contacts from multiple accounts in gmail

Question

I have a rails application and i am using omnicontacts gem to import contacts from yahoo, gmail, and outlook.Its working fine.But once i import contacts from any account say of gmail, and tries to import contacts from another account it does not ask me to login using another account for importing contacts from it. Here is my omnicontacts initializer.Please help, I can add more info if needed.

config/initializers/omnicontacts.rb

Rails.application.middleware.use OmniContacts::Builder do
   importer :gmail, ENV['GMAIL_ID'], ENV['GMAIL_SECRET'], redirect_path: '/invites/gmail/contact_callback', max_results: 1000
   importer :yahoo, ENV['YAHOO_ID'], ENV['YAHOO_SECRET'], callback_path: '/invites/yahoo/contact_callback', max_results: 1000
   importer :outlook, ENV['OUTLOOK_APP_ID'], ENV['OUTLOOK_APP_KEY'], redirect_path: '/invites/outlook/contact_callback', max_results: 1000
end