update code with python >3.6 version Spell

[shoaib-intro]

Hi, I observed there is most frequent error in log parsing drain and spell which is: re.error: bad escape \s at position 0 because of this someone need to install python 3.6. can fix this in spell by replacing splitter = re.sub(' +', '\s+', splitters[k]) with splitter = re.sub(' +', '\\\s+', splitters[k]) #splitter = re.sub(' +', '\s+', splitters[k])?