Accept non-integer statusCode JSON values

[slank]

Description of changes:

The Lambda proxy integration for API Gateway does not specify that statusCode must be an integer, but SAM CLI requires it. This change fixes SAM CLI to accept non-integer status codes that contain integer values.

See slank/awsgi#23 for additional background.

Checklist:

• Write Design Document (Do I need to write a design document?)
• Write unit tests
• Write/update functional tests
• Write/update integration tests
• make pr passes
• Write documentation

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

[sanathkr]

LGTM. Thanks for the fix

[jfuss]

Could you also add integration tests for this? This will help us make sure changes don't regress behavior in the future.

[slank]

I've added an integration test in what I think is the right place. I get S3 client errors trying to run those tests locally so we'll see what Travis says.

[jfuss]

@slank Thanks for adding the tests. Some of our integ-tests require creds, so it's could be either you don't have the correct permissions or no credentials.

[jfuss]

Thanks for the patch 🕺