Convert Guzzle\Http\Message\Header instances to arrays
merged branch davedevelopment/guzzle-headers (PR #107)

This PR was merged into the master branch.

Discussion
----------

Convert Guzzle\Http\Message\Header instances to arrays

I think this changed for Guzzle 3.6, the headers collection is a collection of `Guzzle\Http\Message\Header` instances, rather than arrays.

Commits
-------

68eaf90 Convert Guzzle\Http\Message\Header instances to arrays