Ensuring that we convert REXML values to strings
Adding coverage for origin conversion to Location objects
Base implementation
Added rating
Added address validation
Added shipping labels
Added purchase postage
Added tracking
UPS: Handle delivery not being most recent event.
return false for canned_address_verification_works? if login is nil
Merge pull request #149 from Shopify/fix_nomethoderror_empty_usps_login

USPS: Return false for canned_address_verification_works? if login is nil
Simplify logic, pretty-print xml
Merge remote-tracking branch 'shopify/master' into canada_post_fix
Updating Canada Post test based on PR feedback

After a little bit of discussion, we have decided that
checking the String nature of these properties provide
little value and can be removed.
Merge pull request #146 from akeem/canada_post_fix

Ensure that city, province, and address returned from Canada post are indeed Strings
Merge pull request #148 from jamuraa/delivery-status-not-most-recent

UPS: Handle delivery not being most recent event.
Merge pull request #147 from smartacus/stamps_integration

Stamps integration
USPS address validation