Cdeng/mocha support for lts

[esalman-sfdc]

In the doc whereever we say "sfdx force:lightning:test:run" we may want to add app name as we no longer have any app with default name in the repo.

[cdengSFDC]

$T.createComponent looks like this now:

/**
 * Creates the Lightning component, adds it to the list of components to be cleared,
 * and render it into the specified DOM element.
 * 
 * @param {string} descriptor The descriptor of the component to be rendered.
 * @param {Object.<string, Object>} attributes The attributes to be set to the component.
 * @param {boolean} requiresRendering If component rendering is required. Optional.
 * @returns {Promise} component creation or rendering result, depending on whether renderInto is specified
 */
$T.createComponent = function (descriptor, attributes, requiresRendering) {

User no longer has to worry about the name of the renderInto div, but this also means they can no longer change it.