add EE keys service

app/services/keys/create_service.rb

 module Keys
   class CreateService < ::Keys::BaseService
+    prepend EE::Keys::CreateService
+
     def execute
       key = user.keys.create(params)
       notification_service.new_key(key) if key.persisted?

ee/app/services/ee/keys/create_service.rb

+module EE
+  module Keys
+    module CreateService
+      def initialize(user, params)
+        super(user, params)
+
+        @ip_address = params.delete(:ip_address)
+      end
+
+      def execute
+        super.tap do |key|
+          log_audit_event(key)
+        end
+      end
+
+      def log_audit_event(key)
+        ::AuditEventService.new(@user,
+                                @user,
+                                action: :custom,
+                                custom_message: 'Added SSH key',
+                                ip_address: @ip_address)
+            .for_user(key.title).security_event
+      end
+    end
+  end
+end