Change FastTest nodes from 2 to 4
Increases cubic spline nodes for FastTest to avoid following error:
File "/home/shanika.galaudage/anaconda3/bin/bilby_pipe_generation", line 11, in <module>
load_entry_point('bilby-pipe==0.3.6', 'console_scripts', 'bilby_pipe_generation')()
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 1081, in main
data = DataGenerationInput(args, unknown_args)
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 167, in __init__
self.create_data(args)
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 201, in create_data
self._set_interferometers_from_data()
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 599, in _set_interferometers_from_data
self.interferometers = bilby.gw.detector.InterferometerList(ifo_list)
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 989, in interferometers
self.add_calibration_model_to_interferometers(ifo)
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby_pipe-0.3.6-py3.6.egg/bilby_pipe/data_generation.py", line 972, in add_calibration_model_to_interferometers
n_points=self.spline_calibration_nodes,
File "/home/shanika.galaudage/anaconda3/lib/python3.6/site-packages/bilby-0.6.1-py3.6.egg/bilby/gw/detector/calibration.py", line 82, in __init__
raise ValueError('Cubic spline calibration requires at least 4 spline nodes.')
ValueError: Cubic spline calibration requires at least 4 spline nodes.```