Add possibility to edit created events.

[profan]

People will inevitably make mistakes, add in the possibility to edit created events.

Group compositions, slot count, description, title.

[profan]

Event creation function prepped for modifiying if method is POST, creating if PUT.
routes.py, Line 73

Need to create function which returns event as json to make it easier for populating the interface.

[profan]

Can now return event object as json.