Relocated remaining tests
Fixed billing tests and adjusted headers
Merge pull request #3 from inspiran/master

Relocated tests
Added invoice and invoice item mapping
Fixed an order test
Merge branch 'master' of git://github.com/vespolina/commerce
Merge branch 'master' of github.com:inspiran/commerce
Merge pull request #4 from inspiran/master

started fixing tests and adjusted the invoice manager