build(deps-dev): bump scratch-paint

Bumps [scratch-paint](https://github.com/LLK/scratch-paint) from 0.2.0-prerelease.20200728190940 to 0.2.0-prerelease.20200729212812.
- [Release notes](https://github.com/LLK/scratch-paint/releases)
- [Commits](https://github.com/LLK/scratch-paint/commits)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -110,7 +110,7 @@
     "scratch-audio": "0.1.0-prerelease.20200528195344",
     "scratch-blocks": "0.1.0-prerelease.20200721135911",
     "scratch-l10n": "3.10.20200729030742",
-    "scratch-paint": "0.2.0-prerelease.20200728190940",
+    "scratch-paint": "0.2.0-prerelease.20200729212812",
     "scratch-render": "0.1.0-prerelease.20200723210832",
     "scratch-storage": "1.3.3",
     "scratch-svg-renderer": "0.2.0-prerelease.20200610220938",