Corrected behavior of Spe.pad to be more consistent with number of samples added

Added penalization for mismatch between consecutive delays in L matrix

avoid pandas warnings

solved issue with warble.add_file_info

loads directories alphabetically to avoid os dependent differences in behavior

updated iterator for python 375

deleted __pycache__

updated code to work with python 3.7.5

improved NMF.py

added roll0 function to NMF to avoid circular permutation

correct NMF algorithm while writing method section. Rerun analysis

updated Spe.py

removed older commented code

added scatterplt matrix function to utils

simplified lagged NMF function