Give the vagrant box a nice hostname for testing

Vagrantfile

@@ -7,6 +7,11 @@ Vagrant.configure("2") do |config|
   config.vm.synced_folder "./", "/vagrant", type: "rsync"
 
   config.vm.provision "shell", inline: <<-SHELL
+    # Give that vagrant box an apparently good FQDN
+    echo "local-vagrant.example.com" > /etc/hostname
+    echo "local-vagrant.example.com" > /etc/mailname
+    hostnamectl set-hostname local-vagrant.example.com
+
     # Basic preparations
     apt-get update