seed_run_target.txt example doesn't work

[jmmcd]

There are a couple of issues.

The seed population needs updating to new grammar style - done.

In subtree_parse, the snippet match was failing due to whitespace. I believe we can just strip that whitespace so the match succeeds - done. But code owners, please confirm this makes sense. Here is what I did -- I added rstrip().

    # FIXME I am stripping whitespace from end of
    # params['REVERSE_MAPPING_TARGET'] using rstrip(), as this extra
    # whitespace is preventing the match. See GitHub #137.

    if largest_snippet != params['REVERSE_MAPPING_TARGET'].rstrip():

Remaining error:

alpha:src jmmcd$ python ponyge.py --parameters ../parameters/seed_run_target.txt

Start:	 2021-10-28 09:55:23.442861

Traceback (most recent call last):
  File "ponyge.py", line 31, in <module>
    mane()
  File "ponyge.py", line 21, in mane
    set_params(sys.argv[1:])  # exclude the ponyge.py arg itself
  File "/Users/jmmcd/OneDrive - National University of Ireland, Galway/GitHub/PonyGE2/src/algorithm/parameters.py", line 367, in set_params
    params['SEED_INDIVIDUALS'] = load_population(
  File "/Users/jmmcd/OneDrive - National University of Ireland, Galway/GitHub/PonyGE2/src/operators/initialisation.py", line 491, in load_population
    ind = GE_LR_parser.main()
  File "/Users/jmmcd/OneDrive - National University of Ireland, Galway/GitHub/PonyGE2/src/scripts/GE_LR_parser.py", line 346, in main
    check_ind_from_parser(solution, params['REVERSE_MAPPING_TARGET'])
  File "/Users/jmmcd/OneDrive - National University of Ireland, Galway/GitHub/PonyGE2/src/utilities/representation/check_methods.py", line 96, in check_ind_from_parser
    new_ind = individual.Individual(ind.genome, None)
AttributeError: 'NoneType' object has no attribute 'genome'

I can't fix this, I don't know this area of the code.