[Feat] Show "last updated"

[davipt]

On "Consultar", it would be nice to see the time of the last-updated so we know how state is the information of the status of a fuel station.

there seems to be timestamps on the DB, and on app/Http/Controllers/CacheController.php it should be possible to write the updated timestamp on the cache.JSON file, on the line
$json = FuelStation::all('id', 'name', 'brand', 'long', 'lat', 'repa', 'sell_gasoline', 'sell_diesel', 'sell_lpg', 'has_gasoline', 'has_diesel', 'has_lpg')->toJson();
and then adapt the html+javascript to show the date on the box of the fuel station status

[miguelantoniosantos]

Duplicate of #134