Merge pull request #10 from priyankarani/feature/task-1988

Model and views for instance, website, store and store view #1988
Test Connection of instance with magento #1996

Adds a test connection button to test the connection status to magento.

Task ID: project-1984/task-1996
Review ID: 270001
Merge pull request #11 from prakashpp/feature/task-1996

Test Connection of instance with magento #1996
Map countries in tryton to countries from magento #2001

This patch has implemented a method to search country using magento code
that will return browse record of country if found else will raise
error.

Review ID: 274001