Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Great news for the valley. http://www.bizjournals.com/phoenix/blog/techflash/2016/02/breaking-io-plans-potential-500-million-expansion.html?ana=lnk  Responser: no idea what they do even after reading the article but cool
