ZLint v3.7.1-rc1

[chris]

# ZLint v3.7.1-rc1

The ZMap team is happy to share ZLint v3.7.1-rc1.

Thank you to everyone who contributes to ZLint!

## New Lints
* `e_cabf_ecc_allowed_key_usages` For certificates with ECC public keys, digitalSignature MUST be present and only digitalSignature and keyAgreement key usages are allowed.
* `e_crl_sigalgo_missing_null_params` Checks for mandatory NULL parameters in the SignatureAlgorithm

## Bug Fixes
* Migrate from `crypto/rsa` to `zcrypto/rsa` to resolve an issue when linting certificates using RSA keys.

## Misc
* `ca_is_ca` an update to citations

## Changelog
ec384e2 Adapt to zcrypto RSA library fork (#1045)
77ce217 Add lint to check for NULL parameters in the AlgorithmIdentifier element of CRLs, when mandatory per RFC 4055 (#1040)
e9f6f87 Add cabf tls ecc key usage lint (#1041)
c32a53a update ca_is_ca citations, language, expand test coverage (#1038)

**Full Changelog**:https://github.com/zmap/zlint/compare/v3.7.0...v3.7.1-rc1