Add methods to get ATR for a card or a link.

Implemented for both serial and PCSC readers.

Change-Id: Ic12e4b115d24a8b7e483a5603dd6cec90ad289cc
diff --git a/pySim/transport/pcsc.py b/pySim/transport/pcsc.py
index dc040c5..47c4185 100644
--- a/pySim/transport/pcsc.py
+++ b/pySim/transport/pcsc.py
@@ -56,6 +56,9 @@
 		except NoCardException:
 			raise NoCardError()
 
+	def get_atr(self):
+		return self._con.getATR()
+
 	def disconnect(self):
 		self._con.disconnect()