Python3 compatibility

[sifr01]

Update salamandra.py for compatibility with python3 whilst keeping compatibility with python2.

[sifr01]

Currently, $ python3 salamandra.py throws the following errors:

File "salamandra.py", line 255, in run
resp = process_line(line, self.ui, self.threshold, self.sound)
File "salamandra.py", line 32, in process_line
line = line.split(',')
TypeError: a bytes-like object is required, not 'str'

This is just a typeerror issue which is solved by telling python3 to deal with the data as a string, not as bytes in binary mode.