Creates an app for a specified stack. For more information, see Creating Apps (http://docs.aws.amazon.com/opsworks/latest/userguide/workingapps-creating.html).
Required Permissions: To use this action, an IAM user must have a Manage
permissions level for the stack, or an attached policy that explicitly grants permissions. For more information on user permissions, see Managing User Permissions (http://docs.aws.amazon.com/opsworks/latest/userguide/opsworks-security-users.html).