Core htmx API test

• ajax api Content-Type header override to application/json7ms ‣

  this.server.respondWith('POST', '/test', function(xhr) {
    var params = getParameters(xhr)
    xhr.requestHeaders['Content-Type'].should.equal('application/json;charset=utf-8')
    params.i1.should.equal('test')
    xhr.respond(200, {}, 'Clicked!')
  })
  var div = make("<div id='d1'></div>")
  htmx.ajax('POST', '/test', {
    target: '#d1',
    swap: 'innerHTML',
    headers: {
      'Content-Type': 'application/json'
    },
    values: { i1: 'test' }
  })
  this.server.respond()
  div.innerHTML.should.equal('Clicked!')