added: test for nlp() function to ensure None is returned if there are no matches.
added: test for nlp() function to ensure None is returned if there are no matches.

cpatulea/parsedatetime,cpatulea/parsedatetime,idpaterson/parsedatetime,bear/parsedatetime,philiptzou/parsedatetime,phoebebright/parsedatetime,dellis23/parsedatetime,dellis23/parsedatetime,philiptzou/parsedatetime,kienpham2000/parsedatetime,kienpham2000/parsedatetime