Move projects one directory level up.
Remove passing (default) ssh-username and -key to ansible provider.

The provider has default values, which is exactly what has been
passed here. Remove it to simplify the Vagrantfile.
Remove now unused copy of vagrant insecure key.
Merge branch 'remove-directorylevel'
Creating a simple working example for Vagrant.
Clean up Vagrantfile a bit.
Add a Readme-file.
Rename example `vagrant-simple` to `vagrant-ansible-single`.
Create new example `vagrant-ansible-multi` based on `...-single`.
Commit an almost working version of multi-machine provisioning.

Well, it creates the inventory file and runs a dummy playbook. But this
is an important step.
Make multi-machine provisioning working and update readme-file.
Some minor updates to the Vagrantfile.
Update Read-me files.
Add .gitignore-files.
Git-ignore `vagrant_ansible_inventory`.