Date is now a required attribute for generating an Alert

[crackytsi]

Bug / Feature Request

Work Environment

Question	Answer
OS version (server)	Debian
OS version (client)	10
TheHive version / git hash	4 RC1
Package Type	DEB

Problem Description

Creation of Alerts now requires to set the attribute "date".
In former TheHive Versions this was if not provided automatically set to the current date/time.

Steps to Reproduce

1. Try to create an Alert, e.g
curl -H 'Authorization: Bearer [key]' http://[ip]:9000/api/alert -d '{"title": "Title", "description": "description", "type": "type", "source": "instance1", "sourceRef": "test" -H 'Content-Type: application/json' | json_pp
2. Try the same as in step one, but add date

Possible Solutions

Add date as default is not provided to an alert