Merge pull request #3 from zjmichen/master

Formatting, more tests
add stub for mongodb test
Merge branch 'master' of github.com:dbetke/sentiment-tracker
add some to pending test
separates tests, changes test approach, adds mocha options
adds use collection method to tracker
updates tracker tests
adds usePrefix function to tracker, changes tracker test to use prefix and to check and remove only tweets with the test prefix, updates to use best practices
adds remove database method to tracker, uses method in test tracker to drop the test database when tests are complete
updates tracker.js to track any number of keywords for each subject
updates app.js to set a prefix for redis storage
updates use collection method test, adds get redis results method and corresponding test
Merge branch 'master' of github.com:dbetke/tweet-analyzer
add destroy method to tracker