chore(package): update scratch-vm to version 0.1.0-prerelease.1521481406-prerelease.1521481427
chore(package): update scratch-vm to version 0.1.0-prerelease.1521481406-prerelease.1521481427

Closes #1619
LLK/scratch-gui,LLK/scratch-gui,cwillisf/scratch-gui,cwillisf/scratch-gui,cwillisf/scratch-gui