fixes #3520 nested transactions in yii2 module (#3522)
fixes #3520 nested transactions in yii2 module (#3522)

* fixes #3520 nested transactions in yii2 module

* fixes #3520 use fixtures method for unit tests only

tasselchof/Codeception,hubbyist/Codeception,Codeception/base,Naktibalda/Codeception,kt81/Codeception,Codeception/Codeception,Codeception/base,tasselchof/Codeception,Vreasy/Codeception,janhenkgerritsen/Codeception,sergeyklay/Codeception,Codeception/base,Codeception/Codeception,Vreasy/Codeception,Naktibalda/Codeception,hubbyist/Codeception,janhenkgerritsen/Codeception,pitpit/Codeception,pitpit/Codeception,sergeyklay/Codeception,Naktibalda/Codeception,tasselchof/Codeception,tiger-seo/Codeception,tiger-seo/Codeception,kt81/Codeception