4.0.0 Alpha 4

This release updates the Drupal Driver requirement to the 2.0.0 branch.

• b58d468 - Merge pull request #473 from jhedstrom/195-email-testing
• c7650ab - Merge branch 'master' into 195-email-testing
• 078292e - Merge pull request #477 from jhedstrom/474-composer-test
• 932f297 - Merge pull request #464 from ownsourcing/patch-2
• e571081 - Merge branch 'master' into 195-email-testing
• 05b3c80 - Merge pull request #471 from jhedstrom/470-changelog
• 79bb0ae - Merge pull request #476 from jhedstrom/475-sync-dependency-injection
• 2190203 - Merge branch 'emails' of https://github.com/shrimala/drupalextension into 195-email-testing
• 3def21b - Merge pull request #472 from jnicola/master