Create a semester model for filtering

[donaldong]

In #31, I added two TODO items: to filter the officer and meeting information by the current semester/term. I think one way to do this is by creating a Django data model, specifying the start date and end date. The admins can update the current semester using the admin site, then we can use this information to filter. Thoughts?

[Bonesteeler]

I can see if I can grab a SQL table from work that'll give us semester dates for a few years into the future.

[donaldong]

Oh, Cool!