Xpath not working + issues with adding invitees

const selenium = require("selenium-webdriver");
require('chromedriver');

const url = 'http://port-80-4yp37phzmt.treehouse-app.com/';
const By = selenium.By;
const driver = new selenium.Builder()
                            .forBrowser("chrome")
                            .build();
driver.get(url);

const invitees = [
    'Gonzalo Torres del Fierro',
    'Shadd Anderson',
    'George Aparece',
    'Shadab Khan',
    'Joseph Michael Casey',
    'Jennifer Nordell',
    'Faisal Albinali',
    'Taron Foxworth',
    'David Riesz',
    'Maciej Torbus',
    'Martin Luckett',
    'Joel Bardsley',
    'Reuben Varzea',
    'Ken Alger',
    'Amrit Pandey',
    'Rafal Rudzinski',
    'Brian Lynch',
    'Lupe Camacho',
    'Luke Fiji',
    'Sean Christensen',
    'Philip Graf',
    'Mike Norman',
    'Michael Hulet',
    'Brent Suggs'
 ];

const locators = {
    inviteeForm: By.id('registrar'),
    inviteeNameField: By.css('#registrar input[name="name"]'),
    toggleNonRespondersVisibility: By.css('.main > div input'),
    removeButtonForInvitee: invitee => By.xpath(`//span[text() = "${invitee}"]/../button[2]`)
};

const addInvitee = (name) => {
    driver.findElement(locators.inviteeNameField)
    .sendKeys(name);
    driver.findElement(locators.inviteeForm).submit();
};

const removeInvitee = (invitee) => {
    driver.findElement(locators.removeButtonForInvitee(invitee))
        .click();
};

const toggleNonRespondersVisibility = () => {
    driver.findElement(locators.toggleNonRespondersVisibility)
        .click();
};

invitees.forEach(addInvitee);

removeInvitee('Shadd Anderson');