Add lastName gender specific on ru_RU locale

src/Faker/Provider/ru_RU/Person.php

@@ -154,4 +154,18 @@ public function middleName($gender = null)
             static::GENDER_FEMALE,
         )));
     }
+
+    /**
+     * Return last name for the specified gender.
+     *
+     * @access public
+     * @param string|null $gender A gender of the last name should be generated
+     *     for. If the argument is skipped a random gender will be used.
+     * @return string Last name
+     */
+    public function lastName($gender = null)
+    {
+        return ($gender === static::GENDER_FEMALE) ?
+            static::randomElement(static::$lastName) . 'a' : static::randomElement(static::$lastName);
+    }
 }