Bugfix when header content contains ":"
Added message header configurator
Merge branch 'master' of https://github.com/fervo/FervoDeferredEventBundle into patch-2

Conflicts:
	DependencyInjection/FervoDeferredEventExtension.php
Removed phpunit.xml.dist since it is a duplicate of #8
Merge pull request #3 from Nyholm/patch-2

Bugfix when header content contains ":"