pySim/commands.py: Better type annotations

Change-Id: I68081b5472188f80a964ca48d5ec1f03adc70c4a
diff --git a/pySim/utils.py b/pySim/utils.py
index 22dcda3..9defaf3 100644
--- a/pySim/utils.py
+++ b/pySim/utils.py
@@ -30,6 +30,7 @@
 Hexstr = NewType('Hexstr', str)
 SwHexstr = NewType('SwHexstr', str)
 SwMatchstr = NewType('SwMatchstr', str)
+ResTuple = Tuple[Hexstr, SwHexstr]
 
 def h2b(s: Hexstr) -> bytearray:
     """convert from a string of hex nibbles to a sequence of bytes"""