Improve puppet module

te-agent.cfg file is not managed by an exec anymore which is not recommended.
users can now install specific versions of the te-agent using $version parameter.
init.pp is completely parameterized and variables are evaluated to avoid errors.
Repositories are configured using the APT module which reduces complexity on the code.
Configurations can be managed from hiera.
Dependencies are more clear using $::lsbmajdistrelease facter variable.
add tests skeleton