Merge pull request #1 from prakashpp/develop

Added boilerplate
Merge pull request #2 from sharoonthomas/develop

Add carrier and tests for it
Merge pull request #3 from sharoonthomas/develop

Add methods for get sale & purchase price
Add methods to Sale and Shipments and find_zone_for_address

* Added unit test for find_zone_for_address and scenario test
Merge pull request #1 from vishesh/develop

Initial working module