GitHub and Jenkins only available at project-level

GitHub & Jenkins CI doesn't make sense at the instance-level or
group-level as they are mapping one GitLab project with one GitHub
repository or Jenkins project.

ee/app/models/ee/service.rb

@@ -4,28 +4,27 @@ module EE
   module Service
     extend ActiveSupport::Concern
 
-    EE_SERVICE_NAMES = %w[
-      github
-      jenkins
+    EE_DEV_OR_COM_PROJECT_SPECIFIC_SERVICE_NAMES = %w[
+      gitlab_slack_application
     ].freeze
 
     EE_PROJECT_SPECIFIC_SERVICE_NAMES = %w[
-      gitlab_slack_application
+      github
+      jenkins
     ].freeze
 
     class_methods do
       extend ::Gitlab::Utils::Override
 
-      override :services_names
-      def services_names
-        super + EE_SERVICE_NAMES
-      end
-
       override :project_specific_services_names
       def project_specific_services_names
-        return super unless ::Gitlab.dev_env_or_com?
+        services = super + EE_PROJECT_SPECIFIC_SERVICE_NAMES
 
-        super + EE_PROJECT_SPECIFIC_SERVICE_NAMES
+        if ::Gitlab.dev_env_or_com?
+          services + EE_DEV_OR_COM_PROJECT_SPECIFIC_SERVICE_NAMES
+        else
+          services
+        end
       end
     end
   end

ee/spec/models/service_spec.rb

@@ -3,17 +3,6 @@
 require 'spec_helper'
 
 RSpec.describe Service do
-  describe 'Available services' do
-    let(:ee_services) do
-      %w[
-        github
-        jenkins
-      ]
-    end
-
-    it { expect(described_class.available_services_names).to include(*ee_services) }
-  end
-
   describe '.project_specific_services_names' do
     before do
       allow(::Gitlab).to receive(:dev_env_or_com?).and_return(dev_env_or_com)
@@ -22,13 +11,13 @@ RSpec.describe Service do
     context 'when not on gitlab.com and not in development environment' do
       let(:dev_env_or_com) { false }
 
-      it { expect(described_class.project_specific_services_names).to eq([]) }
+      it { expect(described_class.project_specific_services_names).to contain_exactly('github', 'jenkins') }
     end
 
     context 'when on gitlab.com or in dev environment' do
       let(:dev_env_or_com) { true }
 
-      it { expect(described_class.project_specific_services_names).to eq(%w[gitlab_slack_application]) }
+      it { expect(described_class.project_specific_services_names).to contain_exactly('github', 'gitlab_slack_application', 'jenkins') }
     end
   end
 end