Core htmx AJAX headers

• should include the HX-Trigger header7ms ‣

  this.server.respondWith('GET', '/test', function(xhr) {
    xhr.requestHeaders['HX-Trigger'].should.equal('d1')
    xhr.respond(200, {}, '')
  })
  var div = make('<div id="d1" hx-get="/test"></div>')
  div.click()
  this.server.respond()