chore: Prep for release 3.0.0 (aws#356)

chore: Update version to 2.4.0 (aws#354)

feat: AWS KMS multi-Region Key support (aws#350)

Added new the master key MRKAwareKMSMasterKey
and the new master key providers MRKAwareStrictAwsKmsMasterKeyProvider
and MRKAwareDiscoveryAwsKmsMasterKeyProvider
that support AWS KMS multi-Region Keys.

See https://docs.aws.amazon.com/kms/latest/developerguide/multi-region-keys-overview.html
for more details about AWS KMS multi-Region Keys.
See https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/configure.html#config-mrks
for more details about how the AWS Encryption SDK interoperates
with AWS KMS multi-Region keys.

Co-authored-by: lavaleri <49660121+lavaleri@users.noreply.github.com>

feat: Improvements to the message decryption process (2.x) (aws#343)

See GHSA-x5h4-9gqw-942j

feat: Improvements to the message decryption process (aws#342)

See GHSA-x5h4-9gqw-942j

chore: Prepare for release 2.1.0 (aws#333)

Bump version in identifiers.py and update changelog

chore: Update CHANGELOG.rst for 2.0.0

Merge pull request aws#300 from farleyb-amazon/update-version-1.7.1

Update version identifier to 1.7.1

chore: Update CHANGELOG.rst for 1.7.0

Merge pull request aws#194 from mattsb42-aws/141

1.4.1 release