Setting height property to 1 causes styling bug

[craigpalermo]

Describe the bug
For any component that passes height through to styled-system, setting height={1} results in height: 1px;. This is the expected behavior, so rather than diverge from how styled-system handles height, we should add a runtime warning and update the documentation to better explain the actual behavior in this scenario.

Affected project(s) (e.g. pcln-design-system, pcln-modal, etc.)

• pcln-design-system

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots