Update laravel_app/manifests/init.pp

Added requirement for apache2 to be installed before Exec['clean www directory'] is ran.

When the apache2 package is installed, it places an 'index.html' file in the "/var/www/" folder, which causes the Exec['create laravel project'] to later fail (since the directory is no longer empty).

This change will prevent this from occurring.
Merge pull request #27 from bradstinson/master

Update laravel_app/manifests/init.pp