Hide proposal form until user is authenticated

[winstliu]

This can be done in two ways and is primarily to prevent spam.

The first way is to make the user sign in to their UVa Google account. See images below for an example.
Prompt:

Page:

Then once they're authenticated, show the form. I have the login working (as demonstrated by the above pictures), but they still need to be properly authenticated through the backend to ensure that no spam is sent.

The second option is through Netbadge. This is considerably harder and also necessitates that we get approval through ITS.