Including Dan's new tweets and city files.
Merge with resolved conflicts.
Merge pull request #3 from Murphydbuffalo/SinatraApp

Including Dan's new tweets and city files.
Calculates total tweets across counties in America, displays total tweets, and displays number of tweets in each county on hover.
Search box connected to exchange variables between server.rb and javascript files.
Merge pull request #4 from Murphydbuffalo/frontend

Frontend
Pulled down master, resolved conflicts.
Refactored server.rb by extracting procedural code into methods in tweets.rb.