Add routes for adding/editing announcements

[andrewsosa]

Maybe set the ApiView to allow POST and GET, while PublicApiView only allows GET

[andrewsosa]

~/api/views/hackathon/updates POST (create 1) GET (retrieve all)~ ~/api/views/hackathon/updates/:id GET (retrieve 1), PUT (modify 1)~

See

• https://github.com/andrewsosa/hackfsu_com/blob/issue/issue-39/api/api/views/judge/hacks.py
• https://github.com/hackfsu/hackfsu_com/blob/issue/issue-39/api/api/views/preview/register.py
• https://github.com/hackfsu/hackfsu_com/blob/issue/issue-39/api/api/views/hackathon/get/updates.py

[andrewsosa]

This is going to be integrated into #67

[andrewsosa]

Implemented along with #67 in 20dbfbb304aef9e29015711f1565517634037e1c