hx-headers attribute

• hx-headers overrides inputs9ms ‣

  this.server.respondWith('POST', '/include', function(xhr) {
    xhr.requestHeaders.i1.should.equal('best')
    xhr.respond(200, {}, 'Clicked!')
  })
  var div = make("<div hx-target='this'><input hx-post='/include' hx-headers='\"i1\":\"best\"' hx-trigger='click' id='i1' name='i1' value='test'/></div>")
  var input = byId('i1')
  input.click()
  this.server.respond()
  div.innerHTML.should.equal('Clicked!')