Log Message:
py-cryptography[_vectors]: updated to 2.8

2.8:
* Updated Windows, macOS, and ``manylinux1`` wheels to be compiled with
  OpenSSL 1.1.1d.
* Added support for Python 3.8.
* Added class methods
  :meth:`Poly1305.generate_tag
  <cryptography.hazmat.primitives.poly1305.Poly1305.generate_tag>`
  and
  :meth:`Poly1305.verify_tag
  <cryptography.hazmat.primitives.poly1305.Poly1305.verify_tag>`
  for Poly1305 sign and verify operations.
* Deprecated support for OpenSSL 1.0.1. Support will be removed in
  ``cryptography`` 2.9.
* We now ship ``manylinux2010`` wheels in addition to our ``manylinux1``
  wheels.
* Added support for ``ed25519`` and ``ed448`` keys in the
  :class:`~cryptography.x509.CertificateBuilder`,
  :class:`~cryptography.x509.CertificateSigningRequestBuilder`,
  :class:`~cryptography.x509.CertificateRevocationListBuilder` and
  :class:`~cryptography.x509.ocsp.OCSPResponseBuilder`.
* ``cryptography`` no longer depends on ``asn1crypto``.
* :class:`~cryptography.x509.FreshestCRL` is now allowed as a
  :class:`~cryptography.x509.CertificateRevocationList` extension.