Bugfix: google3 service viewport biasing.

Telling the `::GoogleGeocoder3.geocode` to return only results from in and around a `bound` with the `:bias` option did not work.
Bug example:
```ruby
la_bounds = Geokit::Geocoders::GoogleGeocoder3.geocode('Los Angeles').suggested_bounds
=> #<Geokit::Bounds:0x007fb982b65470 @sw=#<Geokit::LatLng:0x007fb982b65510 @lat=33.7036917, @lng=-118.6681759>, @ne=#<Geokit::LatLng:0x007fb982b65858 @lat=34.3373061, @lng=-118.1552891>>

Geokit::Geocoders::GoogleGeocoder3.geocode('Winnetka', :bias => la_bounds)
=> #<Geokit::GeoLoc:0x007fb982baec10 @all=[#<Geokit::GeoLoc:0x007fb982baec10 ...>], @street_address=nil, @sub_premise=nil, @street_number=nil, @street_name=nil, @city=nil, @state=nil, @zip=nil, @country_code=nil, @province=nil, @success=false, @precision="unknown", @full_address=nil, @lat=nil, @lng=nil>
```
As you can see it returns a `GeoLoc` object with attributes that contain nil values.

These commits fixes the `google3` service:

```Ruby
la_bounds = Geokit::Geocoders::GoogleGeocoder3.geocode('Los Angeles').suggested_bounds
=> #<Geokit::Bounds:0x007ffd043dd660 @sw=#<Geokit::LatLng:0x007ffd043dd688 @lat=33.7036917, @lng=-118.6681759>, @ne=#<Geokit::LatLng:0x007ffd043dd840 @lat=34.3373061, @lng=-118.1552891>>
Geokit::Geocoders::GoogleGeocoder3.geocode('Winnetka', :bias => la_bounds)
=> #<Geokit::GeoLoc:0x007ffd042f0ec8 @all=[#<Geokit::GeoLoc:0x007ffd042f0ec8 ...>], @street_address=nil, @sub_premise=nil, @street_number=nil, @street_name=nil, @city="Los Angeles", @state="CA", @zip=nil, @country_code="US", @province="CA", @success=true, @precision="city", @full_address="Winnetka, Los Angeles, CA, USA", @lat=34.2048586, @lng=-118.5739621, @provider="google3", @district="Los Angeles", @country="United States", @accuracy=4, @suggested_bounds=#<Geokit::Bounds:0x007ffd042eb158 @sw=#<Geokit::LatLng:0x007ffd042eb180 @lat=34.179105, @lng=-118.58832>, @ne=#<Geokit::LatLng:0x007ffd042eb2e8 @lat=34.235309, @lng=-118.5534191>>, @neighborhood="Winnetka">
irb(main):012:0> 
```
Also there was a problems installing the gem with bundler:
```
rake aborted!
cannot load such file -- bundler/gem_tasks

An error occurred while installing geokit (1.6.5), and Bundler cannot continue.
Make sure that `gem install geokit -v '1.6.5'` succeeds before bundling.
```
 I removed the `require "bundler/gem_tasks` and that fixes that problem.