2.0.0.0-dev81

* Framework improvements:
  * Covered the following Magento application components with unit tests:
      * `SalesRule/Model/Observer`
      * `SalesRule/Helper/*`
      * `SalesRule/Model/Plugin/*`
      * `SalesRule/Model/System/Config*`
      * `Sales/Model/Config.php`
      * `Sales/Model/Download.php`
      * `Sales/Model/Quote.php`
  * Covered the following Magento lib form elements with unit tests:
      * `lib/Magento/Framework/Flag.php`
      * `lib/Magento/Framework/Escaper`
      * `lib/Magento/Framework/Event`
      * `lib/Magento/Framework/Logger`
      * `lib/Magento/Framework/Util`
      * `lib/Magento/Framework/Registry.php`
      * `lib/Magento/Framework/Backup/Media`
      * `lib/Magento/Framework/Backup/NoMedia`
      * `lib/Magento/Framework/Archive`
      * `lib/Magento/Framework/Translate.php`
  * Created Service API for Magento_Catalog module:
      * AttributeSet service
      * AttributeSetGroup service
      * ProductLinks service
      * ProductType service
* Paymen...