Filter expired scholarships from API response

[jjhampton]

Feature

Why is this feature being added?

We're wanting to prevent display of expired scholarships on the Scholarships page.The API call to /api/v1/scholarships currently returns all scholarship objects, regardless of whether or not they are expired. To prevent the front-end from displaying the expired scholarships, this would currently require either:
a) Admins to manually remove expired scholarships from the DB, which is time-consuming, prone to human error/forgetfulness, and also would cause us to lose valuable data on scholarships
b) Filter out expired scholarships on the front-end and only show the ones that aren't expired

What should your feature do?

Each scholarship has a close_time property which represents the date when it's old/expired. We can use that date to filter out those expired scholarships from API response, either when fetching from the existing /api/v1/scholarships endpoint (maybe adding some query params to signal that we only want current ones?), or from a new endpoint (something like /api/v1/currentscholarships).
@hpjaj I defer to you on implementation details.

[apex-omontgomery]

Here's three options

1. Manually remove scholarships
2. Filter out at the query level
3. configure the whenever gem to daily remove expired scholarships with a rake task

If a PR contains either the 2nd or 3rd would we consider this a valid acceptance criteria?

[apex-omontgomery]

Placeholder for @colto