Review Board 3.0 introduced new support for "status updates" which are

used to indicate if a review request is undergoing some automated checks

of some kind (for instance, automated code review or pending builds).

These can have a state (such as "pending", "error", "success", and

others), a summary, optional link, and a review (when there are errors).
This adds a new command for working with status updates, helping to

create/update the state of a status update. This command can be run with

rbt status-update.

Debug testing of the --review input on local installation with the following file contents:

{
    "review": {
        "body_top": "Header comment"
    },
    "diff_comment": [
        {
            "filediff_id": 10,
            "first_line": 729,
            "issue_opened": true,
            "num_lines": 1,
            "text": "Adding a comment on a diff line",
            "text_type": "markdown"
        }
    ],
    "general_comments": [
        {
            "text": "Adding a general comment",
            "text_type": "markdown"
        }
    ]
}