Fix error message and handling of doc.sents
Fix error message and handling of doc.sents

aikramer2/spaCy,aikramer2/spaCy,aikramer2/spaCy,recognai/spaCy,explosion/spaCy,spacy-io/spaCy,explosion/spaCy,recognai/spaCy,spacy-io/spaCy,honnibal/spaCy,recognai/spaCy,spacy-io/spaCy,aikramer2/spaCy,honnibal/spaCy,explosion/spaCy,spacy-io/spaCy,recognai/spaCy,explosion/spaCy,aikramer2/spaCy,honnibal/spaCy,explosion/spaCy,explosion/spaCy,honnibal/spaCy,recognai/spaCy,spacy-io/spaCy,spacy-io/spaCy,recognai/spaCy,aikramer2/spaCy