automatic creation of output directories fail in skll 1.5

[benbuleong]

The attached config works for skll 1.1.1 in automatic creation of output directories (log, models, results, predictions) but not in skll 1.5. This feature is very useful when carrying out large number of experiments with different settings with the intention to have different output directories.

[General]
experiment_name = news-UL-WordNet-AutoWeighting
task = evaluate

[Input]
train_directory = toy_set/news/train
test_directory = toy_set/news/test
featuresets = [["UL","WordNet"]]
featureset_names = ["expt"]
learners = ["LogisticRegression"]
suffix = .jsonlines
fixed_parameters = [{'class_weight':'balanced'}]

[Tuning]
grid_search = true
objective = f1_score_least_frequent

[Output]
probability = false
results = results
log = log
models = models
predictions = predictions

[desilinguist]

Addressed by #409.