You don't have to evolve it in RS. That thread was just made to prove if they would evolve in RS, in which they do. To get them to evolve, make them happy! Give them lots of vitamins such as Protein and stuff (but be careful if you're EV training), give it lots of attention by using it in lots of battles (again, be way if you're EV training). To actually account for which one it's going to evolve into, it depends on Personality Value, Gender Value and Nature Value. All of these have hidden numbers, and when added together, lie on a certain range. Espeon has one range, and Umbreon has another. So it's all about which Eevee you picked. Follow the steps above and you should eventually get one of them. ^_^