Add support for auto-complete API

* Add auto-complete support for Google Places

```ruby
client = GooglePlaces::Client.new ENV['GOOGLE_PLACES_API_KEY']
client.predictions_by_input(
      'San F',
      lat: 0.0,
      lng: 0.0,
      radius: 20000000,
      types: 'geocode',
      language: I18n.locale,
)
```