Upgrade to python 3.6

[GerbenJdeBoer]

1. Remove the 2 lines as explained in
   https://stackoverflow.com/questions/3828723/why-should-we-not-use-sys-setdefaultencodingutf-8-in-a-py-script

#DEL# reload(sys)
#DEL# sys.setdefaultencoding('utf-8')

2. Catch the error TypeError: a bytes-like object is required, not 'str' by opening as 'w' instead of 'wb'and by specifying the lineterminator explicitly to remove white lines.

#DEL#with open(full_output_path, 'wb') as f:
#DEL#    w = csv.DictWriter(f, fields)
with open(full_output_path, 'w') as f:
    w = csv.DictWriter(f, fields, lineterminator='\n')