Core htmx API test

• should add class properly after delay21ms ‣

  var div = make('<div></div>')
  div.classList.contains('foo').should.equal(false)
  htmx.addClass(div, 'foo', 10)
  div.classList.contains('foo').should.equal(false)
  setTimeout(function() {
    div.classList.contains('foo').should.equal(true)
    done()
  }, 20)