Error caused by inconsistent bytes/str

[peastman]

When I try to use pyAffy on Python 3.6, it fails with this error:

  File "/home/peastman/pyaffy/pyaffy/process.py", line 141, in rma
    y = parse_cel(cel_file)
  File "pyaffy/celparser.pyx", line 696, in pyaffy.celparser.parse_cel
  File "pyaffy/celparser.pyx", line 614, in pyaffy.celparser.parse_celfile_cc
  File "pyaffy/celparser.pyx", line 523, in pyaffy.celparser.parse_celfile_cc.read_data_header
  File "pyaffy/celparser.pyx", line 490, in pyaffy.celparser.parse_celfile_cc.read_header_param
TypeError: a bytes-like object is required, not 'str'

The error is caused by this line in read_header_param():

 v2 = decode_unicode(v2.rstrip('\x00'))

bytes.rstrip() requires its argument to be a bytes, not a str. The line should be changed to

 v2 = decode_unicode(v2.rstrip(b'\x00'))

and likewise in line 492.