Travis.yml: Fixing misleading regex and using xargs for all cpan operations

Hello @jagtalon @moollaza @crazedpsyc 

This is related to: https://github.com/duckduckgo/zeroclickinfo-goodies/issues/242 I think the original regex doesn't do what the author intended? It looks like the Travis CI build dependencies are actually only resolved by:
```
cpanm  --quiet   --notest  App::DuckPAN command 
```