Install dependencies with ensure_packages function

Install dependencies with ensure_packages function
Add stdlib dependency in Modulefile
The problem is, when any other module tries to install gcc (or build-essential) before it will fail as the package definition is already defined:

    Package[build-essential] is already declared; cannot redeclare at /tmp/packer-puppet-masterless/module-0/gcc/manifests/init.pp:19 on node