So I have updated to Ubuntu 14.04 LTS from 12.04. The problem is that my existing virtual hosts are not working after the upgrade. And yes I have tried

sudo a2ensite test.dev

but it says:

ERROR: Site test.dev does not exist!

This is what I have in the
/etc/apache2/sites-available directory

test.dev       mysite.dev      anothersite.dev

the content of test.dev is

<VirtualHost *:80>

    ServerAdmin webmaster@localhost

    ServerName test.dev

    ServerAlias www.test.dev

    DocumentRoot /var/www/test

</VirtualHost>

and the hosts file

127.0.0.1     test.dev

127.0.0.1     www.test.dev