WIP Preparing to get rid of MailMethod model

Please give a look at the following links:
 - http://guides.spreecommerce.org/release_notes/spree_2_0_0.html#mailmethod-model-no-longer-exists
 - https://github.com/spree/spree/pull/2643

spec/controllers/spree/admin/orders_controller_spec.rb

@@ -179,6 +179,12 @@ describe Spree::Admin::OrdersController do
 
         context "when the distributor's ABN has been set" do
           before { distributor.update_attribute(:abn, "123") }
+          before do
+            Spree::MailMethod.create!(
+              environment: Rails.env,
+              preferred_mails_from: 'spree@example.com'
+            )
+          end
           it "should allow me to send order invoices" do
             expect do
               spree_get :invoice, params

spec/mailers/order_mailer_spec.rb

@@ -19,6 +19,10 @@ describe Spree::OrderMailer do
     ship_address = create(:address, :address1 => "distributor address", :city => 'The Shire', :zipcode => "1234")
     @order1 = create(:order, :distributor => @distributor, :bill_address => @bill_address, ship_address: ship_address, :special_instructions => @shipping_instructions)
     ActionMailer::Base.deliveries = []
+    Spree::MailMethod.create!(
+      environment: Rails.env,
+      preferred_mails_from: 'spree@example.com'
+    )
   end
 
   describe "order confirmation for customers" do

spec/mailers/producer_mailer_spec.rb

@@ -2,6 +2,12 @@ require 'spec_helper'
 require 'yaml'
 
 describe ProducerMailer do
+  before do
+    Spree::MailMethod.create!(
+      environment: Rails.env,
+      preferred_mails_from: 'spree@example.com'
+    )
+  end
   let!(:zone) { create(:zone_with_member) }
   let!(:tax_rate) { create(:tax_rate, included_in_price: true, calculator: Spree::Calculator::DefaultTax.new, zone: zone, amount: 0.1) }
   let!(:tax_category) { create(:tax_category, tax_rates: [tax_rate]) }

spec/models/spree/order_spec.rb

@@ -487,6 +487,13 @@ describe Spree::Order do
 
   describe "scopes" do
     describe "not_state" do
+      before do
+        Spree::MailMethod.create!(
+          environment: Rails.env,
+          preferred_mails_from: 'spree@example.com'
+        )
+      end
+
       it "finds only orders not in specified state" do
         o = FactoryGirl.create(:completed_order_with_totals)
         o.cancel!