Inconsistent role requirement on virtual machine between API and WebUI

[netsandbox]

Environment

• Python version: 3.6.9
• NetBox version: 2.7.6

Steps to Reproduce

1. create virtual machine by API: role is not required
2. create virtual machine in WebUI: role is required

Expected Behavior

If a role for a virtual machine is required or not should be the same for API and WebUI.

Observed Behavior

If you create a virtual machine by API, role isn't required.
If you create a virtual machine in the WebUI, role is required.

The VirtualMachine model defines blank=Trueand null=True, which makes role not required by API:
https://github.com/netbox-community/netbox/blob/v2.7.6/netbox/virtualization/models.py#L212-L219

The VirtualMachineForm doesn't have a required=False for role, which makes role required in the WebUI:
https://github.com/netbox-community/netbox/blob/v2.7.6/netbox/virtualization/forms.py#L352-L360

[hSaria]

You're correct. This happened during some internal housekeeping (#3912). The solution would be to add required=False as you described.