Also convert "metric" temperature unit to degrees.

Author: cmfcmf

Cmfcmf/OpenWeatherMap/Util/Unit.php

@@ -81,7 +81,8 @@ public function __toString()
     public function getUnit()
     {
         // Units are inconsistent. Only celsius and fahrenheit are not abbreviated. This check fixes that.
-        if ($this->unit == 'celsius') {
+        // Also, the API started to return "metric" as temperature unit recently. Also fix that.
+        if ($this->unit == 'celsius' || $this->unit == 'metric') {
             return "°C";
         } else if ($this->unit == 'fahrenheit') {
             return 'F';