Fix save path argument

This makes this consistent with the Benchmarks.

Author: yngtodd

examples/darts/uno/default_model.txt

@@ -1,7 +1,7 @@
 [Global_Params]
 model_name = 'darts_uno'
 data_url = 'http://ftp.mcs.anl.gov/pub/candle/public/benchmarks/Pilot1/uno/' 
-savepath = './results'
+save_path = './results'
 log_interval = 100
 train_data = 'top_21_auc_1fold.uno.h5'
 learning_rate = 0.025