related to #4792, close #4874

ensure it is one of the input values

fixes #4880

[skip ci] Translation of rest-response-formatting.md

fix translation errors

Fixes typos in security-passwords.md

Fixes #4424: Added `inline` and `mimeType` options to all file downloading methods provided in `yii\web\Response`

[ci skip] Russian translation for tutorial-core-validators

[ci skip] controllers guide translated

[ci skip] [Uk][Guide] Add pages translation

 try using the new Docker setup of travis-ci