setTimeout not in pySerial anymore

[Leon-001]

Hi Mathias,
at first: thanks for the great work!

I just had the following problem after upgrading my operating system:
the connection to the EC-Terminal was not possible anymore.

The reason:
The function setTimeout does not exist in current pySerial anymore.

I think it should be changed to
self.connection.timeout = timeout

In the file transmission/transport_serial.py (line 156 and 171)

Kind regards,
Leon

[raphaelm]

My PR #6 fixes this along the way