Config: make more reislient.

Basically set minimum versions for all of the modules and try to do better about getting paths correct.

This was intended to address #153 but I doubt very seriously it has done so.
@mwmiller i think you're missing `->{dir}` here?

I'm getting this error:

```

[04:29 PM codio@teresa-misted zeroclickinfo-spice {master}]$ duckpan query                                                                                                                                                                        
Checking for latest App::DuckPAN ... 0.161 (duckpan has 0.160)                                                                                                                                                                                    
Checking for latest DDG Perl package... 0.130                                                                                                                                                                                                     
Can't call method "is_dir" on unblessed reference at /home/codio/perl5/perls/perl-5.18.2/lib/site_perl/5.18.2/App/DuckPAN.pm line 460.  
```