Work-around for NLTK download issues

[chrisroederucdenver]

test_string_similarity failed for me because the nltk download isn't working. I found a way to get the download to work here:

https://stackoverflow.com/questions/38916452/nltk-download-ssl-certificate-verify-failed

After failing to get the solutions that fix SSL locally, I used the python code that disables SSL for this task.