chore(deps-dev): bump postcss-custom-properties from 8.0.11 to 10.0.0 (#1200)

Bumps [postcss-custom-properties](https://github.com/postcss/postcss-custom-properties) from 8.0.11 to 10.0.0.
- [Release notes](https://github.com/postcss/postcss-custom-properties/releases)
- [Changelog](https://github.com/postcss/postcss-custom-properties/blob/master/CHANGELOG.md)
- [Commits](postcss/postcss-custom-properties@8.0.11...10.0.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: [ Cassondra ] <[email protected]>
Co-authored-by: [ Cassondra ] <[email protected]>

Author: 4 people

package-lock.json

@@ -117,7 +117,7 @@
     "npm-run-all": "^4.1.5",
     "opn": "^6.0.0",
     "polymer-webpack-loader": "^2.0.3",
-    "postcss-custom-properties": "^8.0.11",
+    "postcss-custom-properties": "^10.0.0",
     "prettier": "^1.19.1",
     "pretty-quick": "^2.0.2",
     "react": "^16.13.1",