v0.12.0

Key highlights:

• The compiler keeps its work between compiles, so a mix command with nothing changed skips the Hologram build
• Much lower memory use and faster cold builds on large apps
• Live reload rebuilds only the pages an edit reaches
• Struct code loads on demand, so bundles are much smaller
• Prop validation, with new required and values options
• Props readable in actions through component.props
• A component's actions run one at a time, in dispatch order
• Realtime fixes for HTTP/2 and Bandit

Full release notes:
https://hologram.page/blog/hologram-v0-12