Fix review score logic (#67)

Was incorrectly adding 1 to review count, which was reducing the overall review score

models/Reviews_model.php

@@ -211,6 +211,6 @@ public static function getScoreForLocation($locationId)
             $totalReviews += $totalRatings;
         }
 
-        return $totalWeight / ($totalReviews + 1);
+        return $totalReviews > 0 ? ($totalWeight / $totalReviews) : 0;
     }
 }