Create sign in page

[mirdaki]

We should have a single sign in page for the club. It will be a form where people can enter in their UFL email address and click sign in. It will then communicate to the backend with a REST call (don't worry about that for right now), where it will get one of three messages:

1. Sign in complete, existing member
   • In this case just show a success message and empty the fields so someone else could sign in
2. Sign in complete, new member
   • Their email wasn't in out database, so we will pop up some additional fields (first name, last name, GitHub handle, if they would like to join out email list, if they would allow us to share their sign-in info with ACM) that the user could fill out (all or some of them) and submit or they could hit "no thanks" to not add the information. If they did submit additional info, make sure they get a confirmation as to weather the server sends back a revived reply or not (like in scenario 3).
3. Sign in failed
   • Something went wrong and their sign in was not recorded. You should have a message letting them know, so they can try again if they want.

[jperitz]

Hey, this is something I'd like to work on.

[mirdaki]

Awesome, I'll add you to it! Let me know if you have any questions

[mirdaki]

There has been some update on this (the UI is more refined and does send HTTP messages to an address). Currently on hold while waiting for the back end API to finish

[rennemannd]

I added @swiftlee as this issue was partly addressed by him in the overall react-conversion of the website. The work on the functionality of this page is being worked on further in the feature/auth branch.