Remove minified assets from git

Remove the minified CSS and JS resources for this application from Git,
and instead, generate them when needed on the production machines.
Default games watched to empty

In the case that the user has no games watched, default the array to
empty to avoid a bug.
Refactor game builder logic into super object

Refactor out the common logic from the game builders into a single
object, which both can extend from. This should allow for easier
maintenance in the future.
Move game builders into lib directory

Move the nba/nhl game builders into the lib directory, rather than
their model-builders directory.