Update to PHP8 and add support for mailgun-php ^3.0 (#88)

* Experiments

* Make the logger conditional

* Update dev dependencies

* Add php7.3 version, fix unit tests

* Migrate XML configuration

* Update symfony dependencies

Added Symfony 4 setup (#75)

Prepare for 1.1.0 (#68)

* Prepare for 1.1.0

* Update Changelog.md

Version 1.0.0 marks the first release to require Swiftmailer 6.x

Prepare for 0.4.0 (#42)

Create 0.3.1 that fixes a minor Composer issue

Better event and return value (#30)

* Make sure we use the proper event status

* Dont fix return value and make sure failed recipients get added to the event

* We should assertEmpty instead of assertNull

Merge pull request #18 from inanimatt/patch-1

Fix tag header

Send mailgun headers as post parameters and make sure you can switch …

…domain

Bump version to 0.1.2 as there have been some improvements regarding …

…Mailgun API compatibility