Merge branch 'release/0.4.5' into develop
Updated production URL
Refactor commony used options

Also stops trying to be UPS. Validation of data is
the problem of UPS, not python API
Add rating API
Merge pull request #11 from sharoonthomas/develop

Refactoring and addition of rates API
Fix the base url
Merge pull request #12 from sharoonthomas/develop

Fix the base url
Release version 0.5.0
Merge branch 'release/0.5.0'