Support multiple packages with nil values
Merge pull request #114 from alse/packages_with_nil_values

CanadaPost - Support multiple packages with nil values
UPS correctly parses delivery signature and stores it.
Add FedEx Freight Priority and Economy to service types
Add additional address fields to location node
Add freight rate request support if options present [FedEx]
Fix FedEx unit tests given new location node builder
Add remote test for FedEx freight
Add unit test for FedEx freight rate request
Fix CanadaPost response error fixture
Fix test for canada post non successful response
Properly handle canada post error response
Merge pull request #117 from hensleyl/add_delivery_signature_to_ups

UPS correctly parses delivery signature and stores it.
Use more descriptive variable names for FedEx freight nodes
Refactor FedEx freight-specific request elements to their own functions
Merge pull request #118 from trxtraining/fedex-freight

Add support for FedEx freight economy and priority
Merge pull request #119 from scottlangendyk/canadapost-response-fix

Fix Canada Post error handling
Test passing customer number as constructor option
Allow customer number to be passed as constructor option
Test that carrier customer number can be overriden by rates request options