Features

• assertions: 'not' matcher (#16240) (b838f95), closes #15868
• cloudfront-origins: add custom headers to S3Origin (#16161) (f42b233), closes #16160
• cfnspec: cloudformation spec v40.1.0 (#16254) (fe81be7)
• cli: support --no-rollback flag (#16293) (d763d90), closes #16289
• core: normalize line endings in asset hash calculation (#16276) (01bf6e2)
• ec2: add m6i instances (#16081) (a42a1ea)
• ecs: add support for Fargate PV1.4 ephemeral storage (#15440) (f1bf935), closes #14570
• ecs-patterns: add capacity provider strategies to queue processing service pattern (#15684) (f40e8d6), closes #14781
• ecs-patterns: Allow configuration of SSL policy for listeners created by ECS patterns (#15210) (2c3d21e), closes #11841 #8816
• route53resolver: DNS Firewall (#15031) (ffdcd94)
• stepfunctions-tasks: support allocation strategies in EMR CreateCluster (#16296) (5a5da57), closes #16252
• synthetics: add Python runtime and latest Nodejs runtime (#16069) (de218ba), closes #15138 #16177

Bug Fixes

• apigatewayv2: api mapping key with two hyphens is disallowed (#16204) (0889564), closes #15948
• rds: fromDatabaseInstanceAttributes() incorrectly stringifies ports with tokens (#16286) (41b831a), closes #11813
• core: inconsistent analytics string across operating systems (#16300) (ff6082c), closes #15322
• elasticloadbalancingv2: target group health check does not validate interval versus timeout (#16107) (a85ad39), closes #3703