Better Query on repo.index

## Description and Impact
Changes how repo.index queries for things

## Deploy Plan
> Does Infrastructure need to know anything special about this deploy?

## Rollback Plan
* To roll back this change, revert the merge with: `git revert -m 1 MERGE_SHA` and perform another deploy.

## URLs
> Links to bug tickets or user stories.

## QA Plan
> Fill in scenarios below. Review [QA Best Practices](https://source.sportngin.com/page/show/1227795-qa-best-practices).

#### Risk Level:
- [X] Low
- [ ] Medium
- [ ] High

Rake app:hubstats:setup to build
Checkout that the number of comments and pulls in the active users table add up to the numbers displayed above
You should just use `length` here, `count` will trigger another SQL query. If it were possible that you weren't going to iterate over `@users` later on, then using `count` could make sense because it would save you from creating all of those ActiveRecord objects.