Merge branch 'better-service-migration' into 'master'

Better service migration

Prevent crashes and saving invalid record. Skip non-valid services.

Better fix for https://github.com/gitlabhq/gitlabhq/pull/8199

See merge request !1235

db/migrate/20140907220153_serialize_service_properties.rb

@@ -23,7 +23,7 @@ class SerializeServiceProperties < ActiveRecord::Migration
       associations[service.type.to_sym].each do |attribute|
         service.send("#{attribute}=", service.attributes[attribute.to_s])
       end
-      service.save(validate: false)
+      service.save
     end
 
     remove_column :services, :project_url, :string

db/migrate/20141006143943_move_slack_service_to_webhook.rb

@@ -10,7 +10,7 @@ class MoveSlackServiceToWebhook < ActiveRecord::Migration
         slack_service.properties.delete('subdomain')
         # Room is configured on the Slack side
         slack_service.properties.delete('room')
-        slack_service.save!
+        slack_service.save
       end
     end
   end