Update cryptography requirement from 2.5 to 2.7

[dependabot-preview]

Updates the requirements on cryptography to permit the latest version.

Changelog

Sourced from cryptography's changelog.

2.7 - 2019-05-30

• BACKWARDS INCOMPATIBLE: We no longer distribute 32-bit manylinux1 wheels. Continuing to produce them was a maintenance burden.
• BACKWARDS INCOMPATIBLE: Removed the cryptography.hazmat.primitives.mac.MACContext interface. The CMAC and HMAC APIs have not changed, but they are no longer registered as MACContext instances.
• Updated Windows, macOS, and manylinux1 wheels to be compiled with OpenSSL 1.1.1c.
• Removed support for running our tests with setup.py test. Users interested in running our tests can continue to follow the directions in our development documentation</development/getting-started>.
• Add support for ~cryptography.hazmat.primitives.poly1305.Poly1305 when using OpenSSL 1.1.1 or newer.
• Support serialization with Encoding.OpenSSH and PublicFormat.OpenSSH in Ed25519PublicKey.public_bytes
  <cryptography.hazmat.primitives.asymmetric.ed25519.Ed25519PublicKey.public_bytes> .
• Correctly allow passing a SubjectKeyIdentifier to ~cryptography.x509.AuthorityKeyIdentifier.from_issuer_subject_key_identifier and deprecate passing an Extension object. The documentation always required SubjectKeyIdentifier but the implementation previously required an Extension.

2.6.1 - 2019-02-27

• Resolved an error in our build infrastructure that broke our Python3 wheels for macOS and Linux.

2.6 - 2019-02-27

• BACKWARDS INCOMPATIBLE: Removed cryptography.hazmat.primitives.asymmetric.utils.encode_rfc6979_signature and cryptography.hazmat.primitives.asymmetric.utils.decode_rfc6979_signature, which had been deprecated for nearly 4 years. Use ~cryptography.hazmat.primitives.asymmetric.utils.encode_dss_signature and ~cryptography.hazmat.primitives.asymmetric.utils.decode_dss_signature instead.
• BACKWARDS INCOMPATIBLE: Removed cryptography.x509.Certificate.serial, which had been deprecated for nearly 3 years. Use ~cryptography.x509.Certificate.serial_number instead.
• Updated Windows, macOS, and manylinux1 wheels to be compiled with OpenSSL 1.1.1b.
• Added support for /hazmat/primitives/asymmetric/ed448 when using OpenSSL 1.1.1b or newer.
• Added support for /hazmat/primitives/asymmetric/ed25519 when using OpenSSL 1.1.1b or newer.
• ~cryptography.hazmat.primitives.serialization.load_ssh_public_key can now load ed25519 public keys.
• Add support for easily mapping an object identifier to its elliptic curve class via ~cryptography.hazmat.primitives.asymmetric.ec.get_curve_for_oid.
• Add support for OpenSSL when compiled with the no-engine (OPENSSL_NO_ENGINE) flag.

2.5 - 2019-01-22

• BACKWARDS INCOMPATIBLE: U-label strings were deprecated in version 2.1, but this version removes the default idna dependency as well. If you still need this deprecated path please install cryptography with the idna extra: pip install cryptography[idna].
• BACKWARDS INCOMPATIBLE: The minimum supported PyPy version is now 5.4.
• Numerous classes and functions have been updated to allow bytes-like types for keying material and passwords, including symmetric algorithms, AEAD ciphers, KDFs, loading asymmetric keys, and one time password classes.
• Updated Windows, macOS, and manylinux1 wheels to be compiled with OpenSSL 1.1.1a.
• Added support for ~cryptography.hazmat.primitives.hashes.SHA512_224 and ~cryptography.hazmat.primitives.hashes.SHA512_256 when using OpenSSL 1.1.1.
• Added support for ~cryptography.hazmat.primitives.hashes.SHA3_224, ~cryptography.hazmat.primitives.hashes.SHA3_256, ~cryptography.hazmat.primitives.hashes.SHA3_384, and ~cryptography.hazmat.primitives.hashes.SHA3_512 when using OpenSSL 1.1.1.
• Added support for /hazmat/primitives/asymmetric/x448 when using OpenSSL 1.1.1.
• Added support for ~cryptography.hazmat.primitives.hashes.SHAKE128 and ~cryptography.hazmat.primitives.hashes.SHAKE256 when using OpenSSL 1.1.1.
• Added initial support for parsing PKCS12 files with ~cryptography.hazmat.primitives.serialization.pkcs12.load_key_and_certificates.
• Added support for ~cryptography.x509.IssuingDistributionPoint.
• Added rfc4514_string() method to x509.Name <cryptography.x509.Name.rfc4514_string>, x509.RelativeDistinguishedName
  <cryptography.x509.RelativeDistinguishedName.rfc4514_string>, and x509.NameAttribute <cryptography.x509.NameAttribute.rfc4514_string> to format the name or component an 4514 Distinguished Name string.
• Added ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey.from_encoded_point, which immediately checks if the point is on the curve and supports compressed points. Deprecated the previous method ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers.from_encoded_point.
• Added ~cryptography.x509.ocsp.OCSPResponse.signature_hash_algorithm to OCSPResponse.
• Updated /hazmat/primitives/asymmetric/x25519 support to allow additional serialization methods. Calling ~cryptography.hazmat.primitives.asymmetric.x25519.X25519PublicKey.public_bytes with no arguments has been deprecated.
• Added support for encoding compressed and uncompressed points via ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey.public_bytes. Deprecated the previous method ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers.encode_point.

2.4.2 - 2018-11-21

... (truncated)

Commits

• 9c2637d bump for 2.7 release (#4903)
• c242991 brew update (#4904)
• 770a514 update to latest openssl on travis builders where appropriate (#4900)
• 828581d Added a new packaging test (#4899)
• 463348b update docs with latest info & remove the last ci.cryptography.io stuff (#4898)
• 4f7715b Remove the final vestigates of Jenkins (#4897)
• 98cd156 Add windows to azure wheel builder (#4881)
• ca6a03a Added Windows tests for 3.4-3.7 (#4895)
• 9517e7f set the path so codecov can find coverage on windows (#4896)
• ff4a878 Strip out unused paths for Jenkinsfile (#4894)
• Additional commits viewable in compare view

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