Task: fix docstring for nlp.no_punct
Task: wrap NLTK resources using EAFP style

Instead of attempting to download NLTK data dependencies on package load
in a Look Before You Leap (LBYL) style, we instead create a wrapper
around those resources that use the Easier to Ask Forgiveness Permission
(EAFP) style. This closes gh-2.

By using EAFP style, we are hoping to only access the NLTK downloader
when a resource is missing, otherwise execution continues as normal.
Before, we asked the NLTK downloader during package load if all the
resources were present, potentially causing the NLTK resource index to
be downloaded unintentionally often.