Add setup.py file

Closes #1
Add Tweet model
Change project name in setup.py
Add travis configuration file
Add build status to README
Fix error in .travis.yml naming
Fix error in test command in travis config file
Rename Tweet.py to tweet.py
Add coverage info to tests
Add coverage info to README
Add date to Tweet model

Closes #2
Add TweetProvider for fetching tweets from the feed

Closes #3
Add keys to gitignore