Made Wad and Presss agree about default regions

Fingertips,

Thanks for a great tool! It took me a bit of debugging to set up, and I have a couple pull requests out of that experience.

The first is to make Presss and Wad classes agree about default AWS region.  Presss says:

```
   def region
      config[:region] || 'us-east-1'
    end
```

Wad says 'eu-west-1'.

This PR sets them both to 'us-east-1' the rationale being that those zone users have to dig the hardest to find their zone name because AWS doesn't show it in the s3 domain and calls it 'US Standard' in many of it's docs.

An equally good alternative (that gives a refreshing break from US-centrism :)) would be to document that default behavior. I'd be glad to offer that as a PR instead. Just something that says for sorry saps like me, "If you can't find out the region of your bucket, it's probably 'us-east-1'". 

Hope you'll consider this or let me know what you'd like to see.
--Brad