Vagrant hostnames should be set based on the directory name (by default).

- The hostname set for the VM should only contain letters, numbers, hyphens or dots. It cannot start with a hyphen or dot.

vagrant/TEMPLATE/Vagrantfile

@@ -4,6 +4,7 @@
 IMAGE = 'matefarkas/xenial:base'
 
 Vagrant.configure(2) do |config|
+  config.vm.hostname = Dir.pwd.split('/')[-1]
   config.vm.provider "docker" do |docker|
     docker.image = IMAGE
   end