Introduce "locations" that are assigned to hosting providers

[tortila]

In the future we want to enable multiple locations per provider.
Location should include:

• country,
• city,
• name,
• possibly a geocoded point (to allow displaying on the map)

This task includes:

• modifying Hostingprovider model (remove country field), create a new Location model (that contains the country field) with a reference to the Hostingprovider
• migration of existing data

[tortila]

Introduce "locations" that are assigned to hosting providers

[mrchrisadams]

See also :

#375

[tortila]

Create multiple locations as editable on a provider, and something we can use in the directory