title: How do set environment variable in gradle via task?
body: <p>I have gradle application. And my main gradle-file include some tasks (groovy).
  I need when start a my task - environment variable "LANG" set encoding = ru_RU.koi8-r (for windows, linux), and after the completion of the my task - environment variable contains the initial value (en_US.UTF-8).
  How do it? Help me, please.</p>