Added support for 24:00

## Description and Impact
> Timepicker was able to parse `24:00` when ngModel was changed, but not when the view was changed. This should fix that and add a small test to catch that in the future.

## Deploy Plan
> Does Infrastructure need to know anything special about this deploy? Nope.

## Rollback Plan
* To roll back this change, revert the merge with: `git revert -m 1 MERGE_SHA` and perform another deploy.

## URLs
> [Venue Admin PR](https://github.com/sportngin/venue_admin/pull/116)

## QA Plan
> Review [QA Best Practices](https://source.sportngin.com/page/show/1227795-qa-best-practices).

#### Happy Path Scenarios
> QA has already taken place on Venue Admin

#### Additional Scenarios (Edge Case, Negative, etc.)

#### Regression Scenarios

Actually, if we wanted Moment to follow our wishes more exactly, we could enable strict parsing, which would stop it from being so generous (but it would still parse all the explicitly specified formats, to which I could add 'HH' before 'hm')
I had attempted that previously to fix the bug Katrina found and force Moment to treat overflow times as invalid, but I implemented it incorrectly.