Add response header outcomes

[erikwebb]

Depends on https://github.com/Behat/Mink/pull/623

[stof]

This Mink PR has been replaced with minkphp/Mink#636

[aik099]

Are you sure? The minkphp/Mink#636 is adding methods to WebAssert class in Mink that are then used by this PR to add new methods to MinkContext.

[stof]

There is a typo in my previous comment. It should have been The Mink PR, not This Mink PR

[aik099]

Maybe you should just close the PR is we're no longer plan to continue work on it?

[stof]

Well, this PR is not obsolete. It exposes the new assertions to the Behat land

[aik099]

Then your comment should say this to be 100% clear:

The Mink's PR mentioned in task description was replaced by minkphp/Mink#636.

[stof]

The Mink PR has been merged. the feature is now in Mink 1.7.x-dev. I will wait a bit with this PR to avoid forcing to use a dev version of Mink in the extension.

[danielbachhuber]

@stof Anything I can do to help this land?