Aggiunto supporto a Zebra TC20.

Fix vari.

zebrascannerlibrary/src/main/java/it/integry/zebrascannerlibrary/ZebraBarcodeReader.java

@@ -35,6 +35,8 @@ public class ZebraBarcodeReader implements BarcodeReaderInterface {
             return true;
         } else if(model.equalsIgnoreCase("TC200J")) {
             return true;
+        } else if(model.equalsIgnoreCase("TC20")) {
+            return true;
         } else return false;
     }