a solve method for spacy.tokens.span.span' object has no attribute 'lower_

in backends/spacy_pasrer.py
you can modify the 
line162-163 code as follow:

entity.root.head.head.dep_ == 'pobj' and
 database.is_phrasal_prep(doc[entity.root.head.head.head.i:entity.root.head.i + 1].text.lower())

