Update cryptography to 2.0

[pyup-bot]

There's a new version of cryptography available.
You are currently using 1.9. I have updated it to 2.0

These links might come in handy: PyPI | Changelog | Repo

Changelog

2.0

• BACKWARDS INCOMPATIBLE: Support for Python 3.3 has been dropped.
• We now ship manylinux1 wheels linked against OpenSSL 1.1.0f. These wheels
  will be automatically used with most Linux distributions if you are running
  the latest pip.
• Deprecated the use of signer on
  :class:~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey,
  :class:~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey,
  and
  :class:~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey
  in favor of sign.
• Deprecated the use of verifier on
  :class:~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey,
  :class:~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey,
  and
  :class:~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey
  in favor of verify.
• Added support for parsing
  :class:~cryptography.x509.certificate_transparency.SignedCertificateTimestamp
  objects from X.509 certificate extensions.
• Added support for
  :class:~cryptography.hazmat.primitives.ciphers.aead.ChaCha20Poly1305.
• Added support for
  :class:~cryptography.hazmat.primitives.ciphers.aead.AESCCM.
• Added
  :class:~cryptography.hazmat.primitives.ciphers.aead.AESGCM, a "one shot"
  API for AES GCM encryption.
• Added support for :doc:/hazmat/primitives/asymmetric/x25519.
• Added support for serializing and deserializing Diffie-Hellman parameters
  with
  :func:~cryptography.hazmat.primitives.serialization.load_pem_parameters,
  :func:~cryptography.hazmat.primitives.serialization.load_der_parameters,
  and
  :meth:~cryptography.hazmat.primitives.asymmetric.dh.DHParameters.parameter_bytes
  .
• The extensions attribute on :class:~cryptography.x509.Certificate,
  :class:~cryptography.x509.CertificateSigningRequest,
  :class:~cryptography.x509.CertificateRevocationList, and
  :class:~cryptography.x509.RevokedCertificate now caches the computed
  Extensions object. There should be no performance change, just a
  performance improvement for programs accessing the extensions attribute
  multiple times.

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[coveralls]

Coverage remained the same at 100.0% when pulling 2a47720 on pyup-update-cryptography-1.9-to-2.0 into e3ee1b9 on master.

[pyup-bot]

Closing this in favor of #20