Merge pull request #6 from adamrunner/master

Fixed Shipment nil Dollar Values Should Be Nil, Not 0.00
Merge pull request #7 from adamrunner/master

Modify Shipment.submit to Pass Through Data Error Messages
added promo codes for line items
added attr_accessor and changed line_item_spec
added back require statement in channeladvisor.rb, it went missing..
rolled item_promos into line_items
reworked shipments responses so it always returns the same data
Merge pull request #12 from adamrunner/refactor_shipments

reworked shipments responses so it always returns the same data structure
Merge pull request #11 from adamrunner/line_item_promo

added promo codes for line items
updated the spec/support/credentials.rb -- no longer need the ~/.config/channeladvisor.yml file to run 'rake spec'
Merge pull request #13 from sheetmusicplus/fix-broken-specs

Fix Broken Specs With Updated Spec Support Credentials
Merge branch 'master' of github.com:adamrunner/channeladvisor