Command Block in Dispenser

Put the summary of the bug you're having here

What I expected to happen was...:
When dispensers that have command blocks in them are powered, they should place command blocks to their looking directions.

What actually happened was...:
However, dispensers just spit command blocks out.

Steps to Reproduce:
1. Place a dispenser (Leave space where the dispenser is looking)
2. Put a command block that a command is written in the dispenser
3. Power the dispenser up