title: Default shared folder in vagrant not visible
body: <p>I have a problem with synced folder in Vagrant. My config is really simple:</p>
  
  <pre><code>Vagrant.configure(2) do |config|
    config.vm.box = "ubuntu/xenial64"
    config.vm.network :forwarded_port, guest: 80, host: 8080
    config.vm.synced_folder ".", "/vagrant"
  end
  </code></pre>
  
  <p>Vagrant usually creates <code>/vagrant</code> folder automatically on start - this time it did not happen so I've done it manually.
  But when I create a file in my host system - it's not visible in guest. Any ideas why?</p>
  
  <p>I've succesfully created a similar configuration with:</p>
  
  <pre><code>config.vm.box = "hashicorp/precise64"
  </code></pre>
  
  <p>but it's a little bit outdated and I want to use Ubuntu 16.04.</p>
  
  <p>Is it a problem with my config, vagrant box, or something else?</p>