Bug: Styles don't update immediately

[hgzimmerman]

Description

**I'm submitting a bug report

When styles change in a view function, they take 2 updates to appear in the DOM.
An example project demonstrating this behavior in a minimal fashion can be found here:
https://github.com/hgzimmerman/yew_styles_dont_apply_minimal_example

Expected Results

Updating styles should appear immediately.

Actual Results

A function returning true for its ShouldRender output needs to run twice to cause the styles to update.
Only running it once will not cause an update.

Context (Environment)

• rustc: 1.37.0 (eae3437df 2019-08-13)

• yew: > v0.8.0

• target: wasm32-unknown-unknown

• cargo-web: 0.6.26

• browser if relevant
  Firefox, Chromium (probably not relevant)