Update to willdurand/geocoder version 3.2

[JaimeChavarriaga]

This is an update to the example of traits to support newer versions of willdurand/geocoder (+3.x).

The Geocoder API since 3.x use HTTP Adapters and returns a list of addresses instead of only one. In consequence, the modified example,

• uses the egelon/ivory HTTP Adapter (included by default)
• uses the ProviderAggregator
• and obtains the results from the first address in the response.