Cornice

**Bug fixes**

- support both marshmallow 2.x and 3.x unknown key handling (ergo, 495)

**Internal changes**

- Enable support for Python 3.7
- cornice.errors and validation tests now use the builtin `json` module instead of `simplejson` (okin, 494)
- Cleanup tests (karantan, 488)

- Add traverse support. For more information regarding Hybrid Applications see
[Pyramid documentation](https://docs.pylonsproject.org/projects/pyramid/en/1.9-branch/narr/hybrid.html)
(483).

- Cornice now accepts Marshmallow schemas instead of instances (482, ergo)
- Marshmallow schemas get request object added to their context
during validation (482, ergo)

**New features**

- Add marshmallow request validation support (475, thanks ergo)
- Allow to reuse Pyramid existing routes in services (477, thanks ergo)

**Documentation**

- Make tutorial work for python3 users (471, thanks rvandegrift)

**Internal changes**

- Remove configuration commit (476, thanks ergo)
- Remove mentions of ``text/json`` in tests and docs (478, thanks wjehenddher)

**New features**

- In addition to the ``colander_body_validator``, there are now three more similar validators:
``colander_headers_validator``, ``colander_path_validator``, and
``colander_querystring_validator``.

**Internal changes**

- `six` is now a required dependency.

**Breaking changes**

Please refer to `upgrading docs <https://cornice.readthedocs.io/en/stable/upgrading.html>`_ for detailed migration instructions.

- ``acl`` and ``traverse`` parameters are not supported anymore on services
- Constructors of resource decorated classed must now be ``__init__(self, request, context=None)``

**Enhancements**

- Align Cornice with Pyramid ACL pattern: Dynamic ACLs based
on resource are now possible (452, thanks wjehenddher)

**Bug fixes**

- Disable CSRF check on predicate fallback view (fixes 458)
- Fix to use own validator for Header Accept (fixes 431)