chore(package): update scratch-paint to version 0.2.0-prerelease.20180613212020

Closes #2338

package.json

@@ -96,7 +96,7 @@
     "scratch-audio": "0.1.0-prerelease.1528394075",
     "scratch-blocks": "0.1.0-prerelease.1528907522",
     "scratch-l10n": "3.0.20180611175036",
-    "scratch-paint": "0.2.0-prerelease.20180611155341",
+    "scratch-paint": "0.2.0-prerelease.20180613212020",
     "scratch-render": "0.1.0-prerelease.20180605145739",
     "scratch-storage": "0.5.1",
     "scratch-svg-renderer": "0.2.0-prerelease.20180613184320",