hx-delete attribute

• issues a DELETE request w/ data-* prefix7ms ‣

  this.server.respondWith('DELETE', '/test', function(xhr) {
    xhr.respond(200, {}, 'Deleted!')
  })
  var btn = make('<button data-hx-delete="/test">Click Me!</button>')
  btn.click()
  this.server.respond()
  btn.innerHTML.should.equal('Deleted!')