[#6] Implemented additional features. Tests missing.
[#6] Added test for unallowed method.
[#6] Improved test for unallowed method.
[#6] Added test for failed cowboy_req:chunk() calls.
[#6] Reverted type specification since the state modified is the implementer's.
[#6] Removed file with record definition and used meck to mock cowboy functions.
Merge pull request #9 from inaka/jfacorro.6.additional.features

[#6] Implemented additional features and added tests