chore(package): update scratch-paint to version 0.2.0-prerelease.20180621213404

Closes #2402

package.json

@@ -96,7 +96,7 @@
     "scratch-audio": "0.1.0-prerelease.20180618171838",
     "scratch-blocks": "0.1.0-prerelease.1529499405",
     "scratch-l10n": "3.0.20180611175036",
-    "scratch-paint": "0.2.0-prerelease.20180619182645",
+    "scratch-paint": "0.2.0-prerelease.20180621213404",
     "scratch-render": "0.1.0-prerelease.20180618173030",
     "scratch-storage": "0.5.1",
     "scratch-svg-renderer": "0.2.0-prerelease.20180618172917",