This is the last planned RC release before releasing a stable 4.0!! 🎉 🎉 🎉

BREAKING:

• Replace incompatible collections when merging nested data with mergeDeep() (#1840)
  • This means that mergeDeep() will no longer merge lists of tuples into maps. For more information see #1840 and the updated mergeDeep() documentation.

New:

• Add "sideEffects: false" to package.json (#1661)
• Update Flow types to be compatible with the latest version (#1863)
• Use ES standard for iterator method reuse (#1867)
• Generalize fromJS() and Seq() to support Sets (#1865)

Fixes:

• Fix some TS type defs (#1847)
  • Adds ArrayLike<T> as option to type factory functions and fromJS now returns Collection<unknown> instead of just unknown.
• Fix issue with IE11 and missing Symbol.iterator (#1850)
• Simplify typescript definition files to support all UMD use cases (#1854)