Better test for type of a variable

[kddejong]

Issue #, if available:
aws-cloudformation/cfn-lint#2395

Description of changes:

• More pythonic way of determining a type of a value

Description of how you validated changes:

Checklist:

• Add/update unit tests using:
  • Correct values
  • Bad/wrong values (None, empty, wrong type, length, etc.)
  • Intrinsic Functions
• Add/update integration tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Do these changes include any template validations?
  • Did the newly validated properties support intrinsics prior to adding the validations? (If unsure, please review Intrinsic Functions before proceeding).
    • Does the pull request ensure that intrinsics remain functional with the new validations?

Examples?

Please reach out in the comments, if you want to add an example. Examples will be
added to sam init through https://github.com/awslabs/aws-sam-cli-app-templates/

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[GavinZZ]

Thanks @kddejong for the input. Wondering is this type check change addressing any bug in the repo?

[kddejong]

It's for an issue with cfn-lint. We override the list type so it's still complies with isinstance but not with stricter type check that is there now

[kddejong]

rebased to develop