Cfn-lint

Features
- Update formatters to be similar from JSON and text outputs and modularize for easier growth later
- Don't raise an error with [E3020](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3020) when doing ACM DNS validation registration
- Add rule [E7003](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E7003) to validate that mapping keys are strings.
- Add rule [E1027](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1027) to validate that dynamic reference secure strings are to supported properties
- Add rule [E1004](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1004) to validate that the Template Description is only a string
- Add rule [E6005](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E6005) to validate that an Output Description is only a string
- Add rule [E6012](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E6012) to validate that an Output Description is less than the maximum length
Fixes
- Fix core libraries to handle conditions around resource properties so that the resource and property checks still run
- Fix core libraries to handle the special property type `Tag` so that its checked when a rule is doing a Property Check

Fixes
- Support additional attributes in spec file for [E3002](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3003)
- Check custom resources as if they are 'AWS::CloudFormation::CustomResource' in rule [E3003](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3003)
- Fix [W6001](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W6001) when an ImportValue is used to another function
- Fix [W2501](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W2501) to support the new dynamic reference feature

Features
- Update rule [E3020](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3020) to support CAA and CNAME record checks
- Update specs to ones released on August 16, 2018

Features
- Load all instances of CloudFormationLintRule in a file. Class doesn't need to match the filename anymore
- Allow load yaml to accept a string allowing people to use cfn-lint as a module
- Add rule [W6001](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W6001) to test outputs that are just using an import value
- Update specs to ones released on August 10, 2018
Fixes
- Update [E2507](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2507) to support conditions and using get_values to test all condition paths
- Update [E2521](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2521), [E2523](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2523) to support conditions and using get_values to test all condition paths
- Rewrite [E2503](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2503) to support intrinsic functions and conditions and lower case protocols
- Fix [E1018](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1018) to support Sub inside a Split function
- Fix [E3003](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3003) description messages to be more informative
- Fix [E3001](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3001) to not require parameters when CreationPolicy is used
- Fix SAM region when no region is available from a local AWS profile or environment variable.

Features
- Update rule [E3020](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3020) to support AAAA record checks
Fixes
- Fix many rules that would fail if a sub parameter had a space at the beginning or end
- Fix crashing issues when trying to get resources that aren't properly configured

Features
- Update CloudFormation Specs to July 20th, 2018
Fixes
- Fix an issue with Exclusive resource properties and RDS with Snapshot and Password