chore(package): update scratch-vm to version 0.2.0-prerelease.20190319154833

Closes #4662

package.json

@@ -111,7 +111,7 @@
     "scratch-render": "0.1.0-prerelease.20190312125229",
     "scratch-storage": "1.2.2",
     "scratch-svg-renderer": "0.2.0-prerelease.20190304180800",
-    "scratch-vm": "0.2.0-prerelease.20190318152140",
+    "scratch-vm": "0.2.0-prerelease.20190319154833",
     "selenium-webdriver": "3.6.0",
     "startaudiocontext": "1.2.1",
     "style-loader": "^0.23.0",