In PokemonGo if you are trying get you Eevee to evolve in to Espeon or Umbreon simply use the names Sakura for Espeon and Tamao for Umbreon. This is a reference to the Pokemon anime episode "Troubles Brewing".
Umbreon Have the Eevee Bill gave you evolve into Umbreon because it'll be awhile until you find another Dark Type. Have this Eevee only fight at night. Moveset: Bite, Sand Attack, Quick Attack, Faint Attack, Mean Look.