Copied the working testbot over to exocortex.py.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Updated README with dependencies.  Right now, one actual, one hypothetical.

Tore "figure it out" code out of __main__ in exocortex.py.  All that stuff
is going to stay in the example testbot included in this repo.

The file testbot.responses seems to have been deleted.  Need to fix that.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Made the helper functions into private methods so they'll stay with the class.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Fixed a bug in backing up the response file.  Added a sys.exit() call at
the end of __main__ to make the interpreter happy.

Signed-off-by: The Doctor <drwho@virtadpt.net>