Remove useless test header setup for emails

Once upon a time we needed a helper to set the `from` header of emails.
This is now set in the ApplicationMailer and not necessary any more.

spec/controllers/admin/subscriptions_controller_spec.rb

@@ -4,7 +4,6 @@ require 'spec_helper'
 
 describe Admin::SubscriptionsController, type: :controller do
   include AuthenticationHelper
-  include OpenFoodNetwork::EmailHelper
 
   describe 'index' do
     let!(:user) { create(:user, enterprise_limit: 10) }
@@ -676,7 +675,6 @@ describe Admin::SubscriptionsController, type: :controller do
 
             context "when at least one associate orders is 'canceled'" do
               before do
-                setup_email
                 proxy_order.cancel
               end
 

spec/controllers/spree/admin/orders/invoices_spec.rb

@@ -3,8 +3,6 @@
 require 'spec_helper'
 
 describe Spree::Admin::OrdersController, type: :controller do
-  include OpenFoodNetwork::EmailHelper
-
   describe "#invoice" do
     let!(:user) { create(:user) }
     let!(:enterprise_user) { create(:user) }
@@ -54,7 +52,6 @@ describe Spree::Admin::OrdersController, type: :controller do
           before do
             allow(Spree::OrderMailer).to receive(:invoice_email) { mail_mock }
             distributor.update_attribute(:abn, "123")
-            setup_email
           end
 
           it "should allow me to send order invoices" do

spec/controllers/spree/admin/orders_controller_spec.rb

@@ -3,8 +3,6 @@
 require 'spec_helper'
 
 describe Spree::Admin::OrdersController, type: :controller do
-  include OpenFoodNetwork::EmailHelper
-
   describe "#edit" do
     let!(:order) { create(:order_with_totals_and_distribution, ship_address: create(:address)) }
 

spec/controllers/spree/orders_controller_spec.rb

@@ -3,7 +3,6 @@
 require 'spec_helper'
 
 describe Spree::OrdersController, type: :controller do
-  include OpenFoodNetwork::EmailHelper
   include CheckoutHelper
   include StripeStubs
 
@@ -471,10 +470,6 @@ describe Spree::OrdersController, type: :controller do
                                                distributor: create(:distributor_enterprise))
         }
 
-        before do
-          setup_email
-        end
-
         it "responds with success" do
           spree_put :cancel, params
 

spec/controllers/user_confirmations_controller_spec.rb

@@ -63,8 +63,6 @@ describe UserConfirmationsController, type: :controller do
   end
 
   context "requesting confirmation instructions to be resent" do
-    before { setup_email }
-
     it "redirects the user to login" do
       spree_post :create, spree_user: { email: unconfirmed_user.email }
       expect(response).to redirect_to login_path

spec/controllers/user_registrations_controller_spec.rb

@@ -3,12 +3,6 @@
 require 'spec_helper'
 
 describe UserRegistrationsController, type: :controller do
-  include OpenFoodNetwork::EmailHelper
-
-  before(:all) do
-    setup_email
-  end
-
   before do
     @request.env["devise.mapping"] = Devise.mappings[:spree_user]
   end