Dual boot multiple fedora verions

[Andy Campbell]

Is there an elegant way to install two versions of Fedora at the same 
time ?

I like to keep the existing version running, while I test/setup new 
version, then swap when I'm happy everything is running ok.  Previously 
I've done with a boot loader like Air-Boot  ( http://sourceforge.net/
projects/air-boot/ ) and partitioned my hard drive with

p1  boot1  ( F19)
p2  boot2  ( F20)
p3  LVM
    / for F19
    / for F20
    /home 
    ...

Then told the installer to use the relevant /boot to install the 
bootloader.  However that sort of broke from F18 and I've had to use the 
workaround in bug 872826 to get that to work.

Can I just use grub2 ? to manage booting, I guess one version of F20 will 
have to be the owner.  How will updates work, can they both update the 
grub2 config when the kernel is updated ?  I've googled around and not 
really found any simple solutions. This artificial looks possible, but 
seem to require some manual fiddling around https://
www.happyassassin.net/2014/01/08/how-to-do-manual-multi-boot-
configuration-with-fedora/

I don't think its too much of a mad idea to want to do a staged upgrade 
to next version, and I quite like have a clean install to get rid of all
the stuff I've installed just to play with.

- Any suggestions, or link's I haven't found.

Thanks in advance
Andy