V3 license fields

[russbiggs]

I like the schema used by OpenAddresses for licensing info here:

https://github.com/openaddresses/openaddresses/blob/master/CONTRIBUTING.md#optional-address-tags

I think we could return a JSON object very similar to this from the providers endpoint. From the database side I'm thinking we may want the option to support multiple licenses per provider (or project). This could be relevant for when a license changes over time, e.g. Provider A had license CC by 4.0 2012-2016 and CC by 1.0 2016-. I would think a separate DB table licenses with columns mapping to those listed on openadresses would facilitate this. @caparker

[caparker]

What about something like this for the license table fields? I built on what openaddresses did based on what weve discussed and doing some light research on it. I found this example also helpful
https://datacatalog.worldbank.org/public-licenses

CREATE SEQUENCE IF NOT EXISTS licenses_sq START 10;
CREATE TABLE IF NOT EXISTS licenses (
  licenses_id int PRIMARY KEY DEFAULT nextval('licenses_sq')
  , attribution_entities_id int NOT NULL REFERENCES entities
  , description text -- short descriptive summary
  , url text -- link to the actual text/pdf/copy of license
  , attribution_required boolean DEFAULT 't'
  , share_alike_required boolean DEFAULT 't'
  , commercial_use_allowed boolean DEFAULT 'f'
  , redistribution_allowed boolean DEFAULT 'f'
  , modification_allowed boolean DEFAULT 'f'
  , metadata jsonb
);

https://github.com/openaq/openaq-db/blob/develop-native-partitions/openaqdb/tables/licenses.sql