Remove sudo commands in bootstrap.sh
Fixes #35 and adds a comment about this at the top.
Download nltk packages in IPython as vagrant user

* 4 Example 6. Hacking on Google Plus data in the interpreter with NLTK
    * nltk.download('stopwords')
* More sophisticated sentence detection
    * nltk.download('punkt')
* Part of speech tagging for tokens
    * nltk.download('maxent_treebank_pos_tagger')
* Named entity extraction/chunking for tokens
    * nltk.download('maxent_ne_chunker')
    * nltk.download('words')
* Example 5. Using NLTK’s NLP tools to process human language in blog data)
    * nltk.download('stopwords')
Reverting to run IPython as root for nltk packages
Hopefully someone can find out what was causing this in the future...
Merge pull request #37 from jwsy/master

Config updates for nltk, IPython run as root again