text search for GIN for name and location fields

Taking https://github.com/eHealthAfrica/ebola-call-center-search as
depart repo.

The complete list of searchable (and ngrammed) fields is:

- surname
- othernames
- address_admindivision1
- address_admindivision2
- address_admindivision3
- address_admindivision4
- address_address

- default --> this field contains all the values of the previous
fields and is useful in case of fulltext searcha across all the other
fields

Locations (address) have a value of 'undefined' if not present, and are
normalized using the following mapping:
https://github.com/emig/dashboard-search/blob/773/gin/couch/search/vendor/locations/lookup.js#L3

using gn as country code

Release v0.0.1