Updated phpdoc

Use GeocoderInterface instead of AbstractGeocoder

Author: Briareos

src/Geocoder/Geocoder.php

@@ -77,7 +77,7 @@ public function reverse($latitude, $longitude)
  * Registers a provider.
  *
  * @param \Geocoder\Provider\ProviderInterface $provider
- * @return \Geocoder\AbstractGeocoder
+ * @return \Geocoder\GeocoderInterface
  */
  public function registerProvider(ProviderInterface $provider)
  {
@@ -92,7 +92,7 @@ public function registerProvider(ProviderInterface $provider)
  * Registers a set of providers.
  *
  * @param array $providers
- * @return \Geocoder\AbstractGeocoder
+ * @return \Geocoder\GeocoderInterface
  */
  public function registerProviders(array $providers = array())
  {
@@ -107,7 +107,7 @@ public function registerProviders(array $providers = array())
  * Sets the provider to use.
  *
  * @param string $name A provider's name
- * @return \Geocoder\AbstractGeocoder
+ * @return \Geocoder\GeocoderInterface
  */
  public function using($name)
  {