Auto merge of #5405 - dwijnand:contributing-lint-overrides, r=matklad
authorbors <bors@rust-lang.org>
Sun, 22 Apr 2018 16:38:01 +0000 (16:38 +0000)
committerbors <bors@rust-lang.org>
Sun, 22 Apr 2018 16:38:01 +0000 (16:38 +0000)
Detail how to override lint warnings when compiling tests

alternative to #5403


Trivial merge