Failing GitHub authorisation

GitHubSignIn.ts

import { ScreenCap } from "../../helpers/ScreenCap"
import { Casper } from "casperjs"

export class GitHubSignIn {
    private readonly OAUTH_AUTHORISATION_FORM = '.oauth-review-permissions form[method=post]';

    constructor(private casper: Casper, private screencap: ScreenCap) { }

    login(username: string, password: string): void {
        this.casper
            .then(() => {
                this.casper.fill('form[method=post]', {
                    "login": username,
                    "password": password
                }, true)
            })
            .then(() => {
                this.casper.waitFor(() => this.casper.evaluate(() => document.querySelectorAll(this.OAUTH_AUTHORISATION_FORM)))
            }).then(() => {
                this.casper.test.assertUrlMatch(
                    /github.com\/login\/oauth\/authorize/,
                    "GitHub application authorisation page is displayed");

                this.screencap.take("gitHubAuthorisation.png");
                this.casper.fill(this.OAUTH_AUTHORISATION_FORM, {}, true);
            });
    }
}