Remove .localdomain from hostname

It is not there in staging or production and the difference causes
problems.
Make sure /etc/hostname has correct hostname

The machines in staging and production have 'ubuntu' in `/etc/hostname`
meaning that if they are restarted their hostname will be reset to
'ubuntu'.
Add domain to resolv.conf during vagrant bootstrap

Facter fails to resolve the fqdn if this is not provided.
Merge pull request #133 from alphagov/rmove-localdomain

Remove .localdomain from hostname