Merge pull request cucumber#520 from cucumber/release/v2_4_0

v2.4.0

Merge pull request cucumber#503 from cucumber/release/v2_3

v2.3

Merge pull request cucumber#484 from Draiken/fix-action-mailer

Check for ActionMailer before adding mailer hook

Merge pull request cucumber#466 from mvz/drop-support-for-ruby-2-3

Support for Ruby 2.4 through 2.7

Merge pull request cucumber#443 from cucumber/release/v2

Release v2

Merge pull request cucumber#436 from cucumber/release/v1_8

Cut v1.8

Merge pull request cucumber#412 from cucumber/feature/release_1_7

Feature/release 1.7

Better newlines?

Version 1.5.0

Version 1.4.5