Standalone web client for Scratch
https://github.com/LLK/scratch-www/pull/211: Fix GH-195: Use a spinner component to convey activity while logging in https://github.com/LLK/scratch-www/pull/220: Quiet warnings about keys in Activity component https://github.com/LLK/scratch-www/pull/221: Log Javascript errors to Sentry https://github.com/LLK/scratch-www/pull/226: Update HOC tutorials and linking