For anyone else who might need to know how to do this on Fedora 22.
First, take a backup of your VM, it never hurts. And now I've warned you. 😛
Install the Fedora CD into your VM Disk drive, boot from CD.
Select Troubleshooting
Rescue a Fedora System
At the console confirm your filesystem path. Mine is at /dev/mapper/fedora-root
Changing 10G to whatever file size you need. To decrease use a -#G.
lvm lvresize --verbose --resizefs -L 10G /dev/mapper/vgname-lvname
Let it complete, should only take a bit.
reboot
There you have it, your Fedora Root Partition should now be expanded to whatever size you need.