ppa_options not getting correct default

While working on updating unit tests for apt::ppa, found that if
apt::params hasn't already been included elsewhere, the $options
parameter is not picking up the correct defaults. Updated the code to
set default options after apt::params is included.
This is probably what happens if the `Class['apt']` is not included before doing apt::ppa. We should probably do something more like
```puppet
if ! defined(Class['apt']) { fail 'You have to include the apt class before declaring any apt defined resources' }
```