[tests] Stop counting pickle bytes in ResultSet tests
Between python 2's pickle and cPickle implementations, the various
protocol versions added in python 3, the length of the pickled string is
completely unpredictable.
Instead, do a simple round trip and test a few attributes.
from os.path import join
assert __file__.endswith(join('scripts', 'script3.py')), __file__
assert '__main__' == __name__, __name__
assert ['-vd', '-f', 'FILE.TXT'] == __args__, __args__