Added selector.
-Updates chart to use opponent team name on X-Axis.
-Updates chart to only show home games.
-Updates select to show all NFL teams.
-Cleans up "test" interface.
-Incorporates database to save new information from Sports Data API.
-Uses npm sportsdata module to do so.
-Saves win % and team data in database.
Successfully pulls all team data from MongoDB to client-side.