Repair Tool notices should use WP's notices error, warning, success color scheme

[netweb]

Currently bbPress only supports failed and success statuses returned for each repair tool, that said, both failed and success both use #46b450 green for the left border notice highlight.

The notices should reflect existing WordPress notices color scheme via ​/wp-admin/css/common.css#L1291

.notice-success,
div.updated {
        border-left-color: #46b450;
}

.notice-success.notice-alt {
        background-color: #ecf7ed;
}

.notice-warning {
        border-left-color: #ffb900;
}

.notice-warning.notice-alt {
        background-color: #fff8e5;
}

.notice-error,
div.error {
        border-left-color: #dc3232;
}

.notice-error.notice-alt {
        background-color: #fbeaea;
}

.notice-info {
        border-left-color: #00a0d2;
}

.notice-info.notice-alt {
        background-color: #e5f5fa;
}

[netweb]

Related: See the WordPress styleguide ​https://github.com/helen/wp-style-guide/issues/14 and ​screenshot-4.png