Allow PHP8

feat: support php 8.0 (#7)

* support for php >=8.0

* fix composer.json

Default Message Options

New Features:
Allowed to pass array of default message options to MandillMailer that will be passed in request property message of the message send api call.
https://mandrillapp.com/api/docs/messages.html

comform to Nette\Mail\Mailer interface

• MandrillException extends Nette\Mail\SendException
• dont use deprecated IMailer interface

show http response status in exceptions message

• show http response status in exceptions message (#4)

Fixed handling of Reply-To header

Merge pull request #3 from smartlook/master

fix: Add Reply-To to headers

v3.0.0: nette3 support

Merge pull request #2 from smartlook/master

Nette 3

v2.1.0

added async=true to api calls