Admin can set bugherd API key

app/controllers/spree/admin/general_settings_controller_decorator.rb

@@ -0,0 +1,15 @@
+module Spree
+  module Admin
+    GeneralSettingsController.class_eval do
+    end
+
+
+    module GeneralSettingsEditPreferences
+      def edit
+        super
+        @preferences_general << :bugherd_api_key
+      end
+    end
+    GeneralSettingsController.send(:prepend, GeneralSettingsEditPreferences)
+  end
+end

app/models/spree/app_configuration_decorator.rb

@@ -23,4 +23,7 @@ Spree::AppConfiguration.class_eval do
 
   # Monitoring
   preference :last_job_queue_heartbeat_at, :string, default: nil
+
+  # External services
+  preference :bugherd_api_key, :string, default: nil
 end

spec/features/admin/external_services_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+feature 'External services' do
+  include AuthenticationWorkflow
+
+  describe "bugherd" do
+    before do
+      Spree::Config.bugherd_api_key = nil
+      login_to_admin_section
+    end
+
+    it "lets me set an API key" do
+      visit spree.edit_admin_general_settings_path
+
+      fill_in 'bugherd_api_key', with: 'abc123'
+      click_button 'Update'
+
+      page.should have_content 'General Settings has been successfully updated!'
+      expect(Spree::Config.bugherd_api_key).to eq 'abc123'
+    end
+  end
+end