cosmetic fixes

### Problem 
The active_shipping project has a few stylistic inconsistencies. Let's clean this up since we'll be owning it. Also, this gives me a chance to learn our coding style. Lemme know if I misinterpreted https://vault.shopify.com/Ruby pls. @RichardBlair mentioned to use IRB style for things not in the style guide.

### Solution
Apply non-functional changes to the source.

Protip: https://github.com/Shopify/active_shipping/pull/197/files?w=1 hides boring whitespace changes.
pls2review @Shopify/shipping @costford 
Aligning arguments to the opening of the method call. Doesn't really show in github, but it looks like below in a text editor:
![screen shot 2014-11-07 at 2 23 10 pm](https://cloud.githubusercontent.com/assets/4197943/4958930/93f6e0c6-66b3-11e4-8e44-f3b233718c19.png)

too much?