Update cryptography to 2.2.1

[pyup-bot]

This PR updates cryptography from 2.1.4 to 2.2.1.

Changelog

2.2

~~~~~~~~~~~~~~~~

* **BACKWARDS INCOMPATIBLE:** Support for Python 2.6 has been dropped.
* Resolved a bug in ``HKDF`` that incorrectly constrained output size.
* Added :class:`~cryptography.hazmat.primitives.asymmetric.ec.BrainpoolP256R1`,
:class:`~cryptography.hazmat.primitives.asymmetric.ec.BrainpoolP384R1`, and
:class:`~cryptography.hazmat.primitives.asymmetric.ec.BrainpoolP512R1` to
support inter-operating with systems like German smart meters.
* Added token rotation support to :doc:`Fernet </fernet>` with
:meth:`~cryptography.fernet.MultiFernet.rotate`.
* Fixed a memory leak in
:func:`~cryptography.hazmat.primitives.asymmetric.ec.derive_private_key`.
* Added support for AES key wrapping with padding via
:func:`~cryptography.hazmat.primitives.keywrap.aes_key_wrap_with_padding`
and
:func:`~cryptography.hazmat.primitives.keywrap.aes_key_unwrap_with_padding`
.
* Allow loading DSA keys with 224 bit ``q``.

.. _v2-1-4:

Links

• PyPI: https://pypi.python.org/pypi/cryptography
• Changelog: https://pyup.io/changelogs/cryptography/
• Repo: https://github.com/pyca/cryptography

[pyup-bot]

Closing this in favor of #142