Fixes engine.rb to call activate for decorators.  Also begin to cleanup code formatting.
Merge pull request #13 from jdutil/master

Fixes engine.rb to call activate for decorators, formatting cleanup.
Fix usps address verification bug, and origin address bug.
Improve error handling during checkout & write some basic integration specs.
Remove unused method.
Merge pull request #14 from jdutil/fix_address_verification

Fix usps address verification bug, and origin address bug.