Build, test and run:
    - Install Java 8
    - Install sbt
    - in the project dir:
        > sbt compile
        > sbt test
        > ./run /path/to/userfile /path/to/tweetfile    #linux only
        OR
        > sbt "run /path/to/userfile /path/to/tweetfile"
        
Notes:
    - Stacktraces are logged to twitter-like.log and not displayed to end user

Assumptions:
    - Usernames can contain spaces
    - Usernames can contain "follows" but not as a whole word because of the first assumption - this would be ambiguous
    - Username should match /[a-zA-Z\s-]+/
    - Empty/white space lines are filtered out
    - A user can be listed as following nobody
    - empty users (user follows ,,,) are ignored
    - extra whitespace is cleaned up
    - Tweets can contain ">"
    - Tweets can't be empty
    - Program should stop if format of either of the files is invalid. The user is assumed
        to have knowledge of the file format
    - Tweets from users not mentioned in the users file are ignored