Add Fedora 31 in supported platforms for Docker virtualization

[Tcharl]

Hi,

First, thank you for these roles, they are awesome and I use them (picked up some roles, not the entire collection).

I just downloaded your collection and tested the docker virtualization installation over Fedora 31.
The results are succesful, so I'll PR the modification letting end users use it with this platform.

Best regards,
Charlie

[ghost]

Hi,

First, thank you for these roles, they are awesome and I use them (picked up some roles, not the entire collection).

I just downloaded your collection and tested the docker virtualization installation over Fedora 31. The results are succesful, so I'll PR the modification letting end users use it with this platform.

Best regards, Charlie