AWS allow user to call create-role

If you have root access to your account, you can just write your own policy and attach it to the user (AWS Console => IAM => Users => Add inline policy). Here is an example:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "Stmt1482712489000",
            "Effect": "Allow",
            "Action": [
                "iam:CreateRole"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}