Rui Figueira 958aa5db55 Remove outdated reference to EnvironmentTestUtils
Documentation still refers to the now deprecated `EnvironmentTestUtils`
class instead of `TestPropertyValues` for setting environment values in
tests.

This commit replaces it with `TestPropertyValues` and provides an
equivalent code example.

Closes gh-12711
2018-04-03 14:10:35 +02:00
..
2018-02-27 10:31:05 +01:00