prepare for 2.0.0-rc release.
prepare for 2.0.0-rc release.


andrew-kamenchuk/yii2-twig,yiisoft/yii2-twig,andrew-kamenchuk/yii2-twig,pana1990/yii2-twig,quantum13/yii2-twig,yiijan/yii2-twig,pana1990/yii2-twig,yiijan/yii2-twig,quantum13/yii2-twig