tools/openambit2gpx.py and python v3.6.1

With python 3.6.1 I get an error "TypeError" in calls fOut.write(...etree.toString(trk)...) and fOut.write(... etree.toString(lap) ...), see below.
Putting "etree.toString(trk, encoding='unicode')", "etree.toString(lap, encoding='unicode')" solved this for me.

[heinz@imru tools]$ ./openambit2gpx.py ~/.openambit/log_F88309511D000E00_2018_02_24_19_15_34.log ./test.gpx Traceback (most recent call last): File "./openambit2gpx.py", line 147, in <module> fOut.write(" "+etree.tostring(trk)+"\n") TypeError: must be str, not bytes
[...]
Traceback (most recent call last): File "./openambit2gpx.py", line 253, in <module> fOut.write(" "+etree.tostring(lap)+"\n") TypeError: must be str, not bytes

[benedetto]

I had the same problem and tried the same fix. Unfortunately this fix prevents running the script on python2...

[centic9]

Fixed now in a different way which still allows to run with Python 2.x via PR #209