Merge branch 'master' of https://github.com/sangheestyle/bison
rm: don't need analyzingtweets.py anymore because tweetdataframe has it's main

After refactoring TweetDataframe class, it has it's own main to run it's
responsibility. Therefore, analyzingtweets.py is not needed anymore.
Merge branch 'master' of https://github.com/sangheestyle/bison