integrate 'construct' python library

'construct' is a declarative symmetric encoder/decoder for user
specified binary formats.  It should come in extremely handy in
tools like pySim.

We start the integration by adding transport methods for transceiving
APDUs with built-in encoding of the command data and decoding of the
response data.

Change-Id: Ibf457aa8b9480a8db5979defcfafd67674303f6c

setup.py

@@ -13,7 +13,8 @@ setup(
         "serial",
         "pytlv",
         "cmd2",
-        "jsonpath-ng"
+        "jsonpath-ng",
+        "construct",
     ],
     scripts=[
         'pySim-prog.py',