Merge pull request #55 from tarunbhardwaj/develop

Postage price should be calculated from PostagePrice node
Integration with trytond-shipping #5974
Merge pull request #52 from priyankarani/develop

Integration with trytond-shipping
Fix installation of trytond-shipping
Merge pull request #56 from aroraumang/develop

Fix installation of trytond-shipping
Explicitly specify weight_uom for rates weight calculation