Skeleton horse is not spawned

The skeleton horse does not spawn with lightning striking a horse, both in creative and survival

What I expected to happen was...:
Falling a distance on a horse, using command or causing the beam to fall naturally, it turns into a skeleton horse

What actually happened was...:
Lightning strikes the horse and causes it to catch fire

Steps to Reproduce:
1. Spawn a horse
2. Make a lightning strike with command, put the time to thunder or wait for a lightening rain
3. If you have changed the time or expected to happen a rain with lightning, wait a lightning strike on a horse