On 15w34b, I made Custom Mob Spawners. When I clicked the command block to make it, the entity inside was a PIG. even thought I clearly put id Skeleton.I made simpler ones but no luck. all are pig spawners

My Command: /setblock ~ ~1 ~ minecraft:mob_spawner 0 replace {SpawnPotentials:[

{Type:Skeleton,Weight:1}

,

{Type:Zombie,Weight:1}

]}

It was a Pig Spawner Again. Anyway, Ive tried lots of other ways but it simply doesn't work anymore. Ive tried "EntityID: and SpawnPotentials, it doesn't work! If you know how to fix this, tell me how!