Name modules according to puppet guidelines

We are using hyphens in our module names. We shouldn't do that.

http://docs.puppetlabs.com/puppet/latest/reference/modules_fundamentals.html

>   Allowed Module Names
>
>   Module names should only contain lowercase letters, numbers, and underscores,
>   and should begin with a lowercase letter; that is, they should match the
>   expression [a-z][a-z0-9_]*. Note that these are the same restrictions that
>   apply to class names, but with the added restriction that module names cannot
>   contain the namespace separator (::) as modules cannot be nested.