Added reference to author of als_baseline method

analysis/database.py

@@ -19,6 +19,12 @@ along with this program, see COPYING.
 If not, see <https://www.gnu.org/licenses/>.
 """
 
+"""
+The als_baseline method, including the WhittakerSmoother Class was taken from
+https://github.com/all-umass/superman/blob/master/superman/baseline/als.py 
+with permission from github user CJ Carey (perimosocordiae)
+"""
+
 from PyQt5 import QtWidgets, QtCore
 import numpy as np
 import sys