That's great! If you wish you may also contact Apple Support regarding upgrading OS. They will certainly check and assist you accordingly.
Not only just Lightroom cc / 6 , almost all CC 2015 Apps like Photoshop CC 2015 , Illustrator CC 2015.....etc requires minimum Mac OS X 10.9 .
It is ideal to Upgrade to Yosemite . Time to say good bye to Lion and say Hello to Yosemite lol .