chore(package): update scratch-paint to version 0.2.0-prerelease.20180404190532

Closes #1720

package.json

@@ -91,7 +91,7 @@
     "scratch-audio": "0.1.0-prerelease.1516198804",
     "scratch-blocks": "0.1.0-prerelease.1522264400",
     "scratch-l10n": "2.0.20180108132626",
-    "scratch-paint": "0.2.0-prerelease.20180403230109",
+    "scratch-paint": "0.2.0-prerelease.20180404190532",
     "scratch-render": "0.1.0-prerelease.1522346711",
     "scratch-storage": "0.4.0",
     "scratch-vm": "0.1.0-prerelease.1522355889-prerelease.1522355906",