Gutenberg: Spacer height input steps in 10 not 1

[ninetyninew]

Describe the bug
The spacer block height input steps in 10, why should the user be limited in increments of 10? What if they wanted a spacer that was 15px?

To reproduce
Steps to reproduce the behavior:

1. Add a spacer block
2. Use up/down arrows on number input
3. Notice it steps in increments of 10

Expected behavior
Steps of 1 to allow any height to be entered.

Editor version (please complete the following information):

• WordPress version: 5.4.1
• Does the website has Gutenberg plugin installed, or is it using the block editor that comes by default? Default

[talldan]

I've labeled as a bug, but it'd be good to get some design feedback on how exactly this should work.

[ninetyninew]

I've also noticed this has a minimum value allowed of 20 applied - it's really limiting.

[MichaelArestad]

I'm really curious as to why it is in increments of 10 as well. I'm going to spin up a quick PR to resolve this in the meantime.