Fix CDK deployment output in CircleCI

[leothomas]

CDK has implemented some output when deploying a template that breaks inside of CircleCI and prints all characters one by one, vertically:

Issue in CDK: https://github.com/aws/aws-cdk/issues/8893.

Possible solution using a CI environment variable when deploying

[leothomas]

Added CI=1 as environment variable to CircleCI - to monitor