0.12.0

• Output modern JavaScript with --format modern (#413, thanks @JoviDeCroock & @marvinhagemeister)
• --define can now replace expressions (#348, thanks @jviide)
• a new --css-modules option controls whether .css files are modular by default (#370, thanks @maraisr)
• the "source" package.json field can now be an Array (#372, thanks @maraisr)
• no more warnings about deprecations or built-ins
• moved to Rollup 2 (#361, thanks @ForsakenHarmony)
• switched from Bublé to Babel (#362, thanks @wardpeet & @ForsakenHarmony)
• added support for babel-macros (#268, thanks @FezVrasta & @ForsakenHarmony)
• Add support for customizing the mangle.json file path (#432, thanks @andrewiggins & @ForsakenHarmony)
• Improvements and corrections for generated TypeScript filenames and definitions (#587 etc)

Breaking Changes

• .babelrc is now detected and supported - it was previously ignored.
• Microbundle now requires Node 10+