Only include EmailHelpers in mailer specs and specs using them

spec/models/ci/pipeline_spec.rb

 require 'spec_helper'
 describe Ci::Pipeline, models: true do
+  include EmailHelpers
+
   let(:project) { FactoryGirl.create :empty_project }
   let(:pipeline) { FactoryGirl.create :ci_empty_pipeline, status: 'created', project: project }

spec/models/project_services/pipeline_email_service_spec.rb

 require 'spec_helper'
 describe PipelinesEmailService do
+  include EmailHelpers
+
   let(:pipeline) do
     create(:ci_pipeline, project: project, sha: project.commit('master').sha)
   end

spec/requests/api/issues_spec.rb

@@ -2,6 +2,7 @@ require 'spec_helper'
 describe API::API, api: true  do
   include ApiHelpers
+  include EmailHelpers
   let(:user)        { create(:user) }
   let(:user2)       { create(:user) }

spec/services/issues/update_service_spec.rb

@@ -2,6 +2,8 @@
 require 'spec_helper'
 describe Issues::UpdateService, services: true do
+  include EmailHelpers
+
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
   let(:user3) { create(:user) }

spec/services/merge_requests/update_service_spec.rb

 require 'spec_helper'
 describe MergeRequests::UpdateService, services: true do
+  include EmailHelpers
+
   let(:project) { create(:project) }
   let(:user) { create(:user) }
   let(:user2) { create(:user) }

spec/services/notification_service_spec.rb

 require 'spec_helper'
 describe NotificationService, services: true do
+  include EmailHelpers
+
   let(:notification) { NotificationService.new }
   around(:each) do |example|

spec/spec_helper.rb

@@ -32,7 +32,7 @@ RSpec.configure do |config|
   config.include LoginHelpers, type: :feature
   config.include SearchHelpers, type: :feature
   config.include StubConfiguration
-  config.include EmailHelpers
+  config.include EmailHelpers, type: :mailer
   config.include TestEnv
   config.include ActiveJob::TestHelper
   config.include ActiveSupport::Testing::TimeHelpers

spec/workers/build_email_worker_spec.rb

 require 'spec_helper'
 describe BuildEmailWorker do
+  include EmailHelpers
   include RepoHelpers
   let(:build) { create(:ci_build) }

spec/workers/emails_on_push_worker_spec.rb

@@ -2,6 +2,7 @@ require 'spec_helper'
 describe EmailsOnPushWorker do
   include RepoHelpers
+  include EmailHelpers
   include EmailSpec::Matchers
   let(:project) { create(:project) }

spec/workers/pipeline_notification_worker_spec.rb

 require 'spec_helper'
 describe PipelineNotificationWorker do
+  include EmailHelpers
+
   let(:pipeline) do
     create(:ci_pipeline,
            project: project,