Remove defaults for search radius and location.

By using LatLng(0, 0) as the default location, react-geosuggest was biasing
results to the Gulf of Guinea.

When radius and location are not supplied to Google's AutocompleteService, it
biases results based on the estimated location of the clients IP address.

src/Geosuggest.jsx

@@ -16,7 +16,7 @@ const Geosuggest = React.createClass({
       disabled: false,
       className: '',
       location: null,
-      radius: 0,
+      radius: null,
       bounds: null,
       country: null,
       types: null,
@@ -133,11 +133,17 @@ const Geosuggest = React.createClass({
     }
 
     var options = {
-      input: this.state.userInput,
-      location: this.props.location || new this.googleMaps.LatLng(0, 0),
-      radius: this.props.radius
+      input: this.state.userInput
     };
 
+    if (this.props.location) {
+      options.location = this.props.location;
+    }
+
+    if (this.props.radius) {
+      options.radius = this.props.radius;
+    }
+
     if (this.props.bounds) {
       options.bounds = this.props.bounds;
     }