In this game, happiness and affection are not the same. Umbreon needs happiness to evolve, which is increased by walking, using the Soothe Bell, Happiness O-Power, leveling up and taking vitamins (Protein, Calcium and Zinc etc). Pokemon Amie has nothing to do with happiness and instead increases affection, and the only Eeveelution to need affection is Sylveon. Also, the Soothe Bell is found in Shalour City, so it will be accessable soon. Vitamins are found in the Battle Maison for 2BP each, or in Laverre City for 9800 Pokedollars each. Befriending O-Power is found in Coumarine City.