Release v1.3.1

What's Changed

• Update some docs by @kddejong in #3314
• Update policy can have non strict types by @kddejong in #3315
• Add AWS::SSM::Parameter::Value to use AllowedPattern by @kddejong in #3332
• Allow Fn::GetAtt to be an array in Join by @kddejong in #3333
• Skip empty strings in action validation by @kddejong in #3337
• Don't validate dynamic references inside fn by @kddejong in #3335
• Only escape type checking for pkg params when strict types is false by @kddejong in #3338
• Remove additionalItems in prefix validation by @kddejong in #3339
• Remove pattern from tag key/value validation by @kddejong in #3341
• Add logic to ImageId format for SSM by @kddejong in #3340
• Remove Refs to yourself in Fn::Sub by @kddejong in #3342
• Update resource pattern for policy validation by @kddejong in #3343
• Update logic on GetAtts for resources that have all attrs by @kddejong in #3344
• Allow capital letters for rule W3687 by @kddejong in #3345
• Skip getatt validation with custom resources by @kddejong in #3346
• Remove AWS::EC2::LaunchTemplate requiredXor value for data by @kddejong in #3347
• Update Null conditions to be scalar or singular by @kddejong in #3349
• Condition satisfaction checks to raise error when unknown by @kddejong in #3350
• Remove / as valid escape in yaml by @kddejong in #3331
• Update CodeBuild::Project FilterGroup types by @kddejong in #3351
• Update SQS MessageRetentionPeriod minimum by @kddejong in #3355
• Backwards compatiblity for cloudformation-cli module validation by @kddejong in #3354
• Allow OAI IDs in IAM policies by @kddejong in #3357

Full Changelog: v1.3.0...v1.3.1