Elections revamp

[jameslzhu]

Tangentially related to #52.

We have an older candidate project, #23, which added an elections page. I think this app needs some refactoring to accomodate committees, committee officer counts, and positions which may vary over time.

Concretely, this means that you would have to:

• Create a Committee model (ideally, reuse the one from Officer cleanup #21)
• Adjust the code / forms to accomodate a varying number of officers (since this changes semester-to-semester, it would be impractical to encode a limit / number anywhere in the code, including in the Committee model, instead allowing any number of officers to be elected any election)
• Create a Position model (idk, you should see if this works or not) which refers to the position people are elected to: officer, assistant officer, committee. Currently in the hkn-rails site this is a string, but strings are easy to mess up. A link to a database object as a ForeignKey would be harder to mess up.
• (optional) create an Committeeship model, tied to a specific semester and a committee, so that a single person would have multiple Committeeship (i.e. the Committeeship model should have a ForeignKey to a user), and use that to codify people's election to a position
• Rewrite the election form with all of these changes
• (optional) create an election log, noting who was nominated to each position in addition to who was elected.

I'm judging this as an easy project due to the limited amount of design work for this; code-wise this is a highly constrained project (you're refactoring code, if the code works as before you're doing it right) but does need you to learn how Django models and forms work.

Pretty minimal UI experience needed.