/**
* Borra la amistad
*
* @param Friend $friendship La amistad a ser borrada
* @throws PDOException si ocurre algun error en la BD
* @return void
*/
public function deleteFriendship($friendship)
{
$stmt = $this->db->prepare("DELETE from friends WHERE userEmail=? and friendEmail=?");
$stmt->execute(array($friendship->getUserEmail(), $friendship->getFriendEmail()));
}