no support for ubuntu 16.04

[pablodav]

When tested with molecule:

ansible-centos7               : ok=33   changed=0    unreachable=0    failed=0
ansible-debian8               : ok=33   changed=21   unreachable=0    failed=0
ansible-trusty                   : ok=35   changed=22   unreachable=0    failed=0
ansible-ubuntu-latest      : ok=4    changed=0    unreachable=0    failed=1   

Actually ubuntu/latest is failing in molecule tests:

failed: [ansible-ubuntu-latest] (item=[u'apache2', u'php5-gd', u'libgd2-xpm-dev', u'libapache2-mod-php5', u'unzip']) => {"failed": true, "item": ["apache2", "php5-gd", "libgd2-xpm-dev", "libapache2-mod-php5", "unzip"], "msg": "No package matching 'php5-gd' is available"}

I will try to fix once get time for it