Remove useless clearing of test emails

They are cleared by the test environment anyway.

spec/lib/spree/core/mail_interceptor_spec.rb

@@ -10,13 +10,7 @@ describe Spree::OrderMailer do
   end
   let(:message) { Spree::OrderMailer.confirm_email_for_shop(order) }
 
-  before(:all) do
-    ActionMailer::Base.deliveries.clear
-  end
-
   context "#deliver" do
-    after { ActionMailer::Base.deliveries.clear }
-
     it "should use the from address specified in the preference" do
       Spree::Config[:mails_from] = "no-reply@foobar.com"
       message.deliver_now

spec/mailers/enterprise_mailer_spec.rb

@@ -6,10 +6,6 @@ describe EnterpriseMailer do
   let!(:enterprise) { create(:enterprise) }
   let!(:user) { create(:user) }
 
-  before do
-    ActionMailer::Base.deliveries = []
-  end
-
   describe "#welcome" do
     it "sends a welcome email when given an enterprise" do
       EnterpriseMailer.welcome(enterprise).deliver_now

spec/mailers/order_mailer_spec.rb

@@ -153,14 +153,6 @@ describe Spree::OrderMailer do
                                      special_instructions: shipping_instructions)
     }
 
-    after do
-      ActionMailer::Base.deliveries.clear
-    end
-
-    before do
-      ActionMailer::Base.deliveries = []
-    end
-
     describe "for customers" do
       it "should send an email to the customer when given an order" do
         Spree::OrderMailer.confirm_email_for_customer(order.id).deliver_now

spec/mailers/user_mailer_spec.rb

@@ -5,14 +5,6 @@ require 'spec_helper'
 describe Spree::UserMailer do
   let(:user) { build(:user) }
 
-  after do
-    ActionMailer::Base.deliveries.clear
-  end
-
-  before do
-    ActionMailer::Base.deliveries = []
-  end
-
   describe '#signup_confirmation' do
     it "sends email when given a user" do
       Spree::UserMailer.signup_confirmation(user).deliver_now

spec/services/place_proxy_order_spec.rb

@@ -56,8 +56,6 @@ describe PlaceProxyOrder do
       end
 
       it "records an issue and ignores it" do
-        ActionMailer::Base.deliveries.clear
-
         expect(summarizer).to receive(:record_issue).with(:complete, order).once
         expect { subject.call }.to_not change { order.reload.state }
         expect(order.payments.first.state).to eq "checkout"

spec/system/consumer/authentication_spec.rb

@@ -125,7 +125,6 @@ describe "Authentication" do
 
         describe "forgetting passwords" do
           before do
-            ActionMailer::Base.deliveries.clear
             select_login_tab "Forgot Password?"
           end