v2.1.0

Added

• Starter and Premium subscriptions are live.
• Added authenticators for handling permissions.
• Installed Raygun for error monitoring.
• Per-user email preferences for new features and updates.
• Slack reporting of new users and subscription changes.
• Icons in navbar dropdown menu items.

Changed

• Hyperlinks from users in markdown will now open in a new window.
• Shared universes now show all content in that universe, rather than just the core content types.
• Improved user profile page design.
• Abstracted out logic from User model to HasContent concern to clean it up.

Fixed

• Users need to be logged in to try exporting their notebook.
• Fixed a few other pages that weren't redirecting to login for logged-out users.
• Universes now export the correct name on related content, instead of "Universe".
• Couple typos in serendipitous questions.
• Javascript loading on some pages.