_Result.excinfo is deprecated

[goodboy]

See pytest-dev/pluggy#155.
A deprecation warning will be emitted until this is changed.

[pytestbot]

GitMate.io thinks possibly related issues are #730 (deprecating --genscript), #830 (deprecate resultlog), #3704 (Deprecate yield_fixtures), #2803 (Deprecate TerminalReporter._tw), and #3050 (deprecate pytest.config).

[nicoddemus]

Closing after pytest-dev/pluggy#155.