Hipaway-Travel/HipMandrillBundle — pull request #5 by ruudk (2013-06-17 16:06:57+00:00)
Title: Removed addHeader restrictions because it's allowed

It's allowed. I've added some custom headers and they just work :)

Just received this from Mandrill:
````
Hello Ruud,

...
That said, you may set those headers in the headers array without any further action. We'll look at getting the documentation for the accepted headers updated.

Let us know if you have additional questions.

The Mandrill Crew
````