Bump scratch-paint

Bumps [scratch-paint](https://github.com/LLK/scratch-paint) from 0.2.0-prerelease.20200514182959 to 0.2.0-prerelease.20200515190220.
- [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.20190925183642",
     "scratch-blocks": "0.1.0-prerelease.20200512201140",
     "scratch-l10n": "3.9.20200512220101",
-    "scratch-paint": "0.2.0-prerelease.20200514182959",
+    "scratch-paint": "0.2.0-prerelease.20200515190220",
     "scratch-render": "0.1.0-prerelease.20200512203149",
     "scratch-storage": "1.3.3",
     "scratch-svg-renderer": "0.2.0-prerelease.20200507183648",