Fix/make bootable

commented the komposer-role out
doesn't use virtualenv for modoboa
fixed other errors (symlink for apache en nginx)
if you write `command: a2ensite 000-default` the command will always be executed (and detected as changed) when you run the playbook.

If you write `command: a2ensite 000-default creates=/etc/apache/sites-enabled/000-default.conf` the command will only be run if  `/etc/apache/sites-enabled/000-default.conf` does not exist.

So, you'd probably end up with:

    - name: enable default sites
      command: a2ensite {{ item }} creates=/etc/apache2/sites-enabled/{{ item }}.conf
      with_items:
        - 000-default
        - 000-default-ssl