Add keyBy(), rename(), defaults(), util/pipeIf()

• Add keyBy()
• Add rename()
• Add defaults()
• Add util/pipeIf()
• No breaking changes

Fix sortBy() mutations

• sortBy() on arrays was mutating, but is now immutable
• No breaking changes

Fix array reverse(), sort() mutations

• reverse() and sort() on arrays were mutating, but are now immutable
• No breaking changes

Add composeWith(), toIndexed(), toKeyed(), updateInto(), defaults()

• Add util/composeWith()
• Add toIndexed()
• Add toKeyed()
• Add updateInto()
• Add defaults()
• No breaking changes

Fix flatMap()

• Fix flatMap() on empty collections
  • Was returning undefined instead of an empty version of the original collection
• No breaking changes

Add sort() and sortBy()

• Add sort() and sortBy()
  • Please note that these methods cannot work with objects, even though they work with Immutable.js Maps
• No breaking changes

Perf gains and better error messages

• Rewrite prep to be more performant, only perform the type checks that the current function has methods for.
• Add names and rename item vars to value to match docs
• Error message to always say what the original method name was (not a nested method name) and the value it was passed.
• No breaking changes

Fix flow and build issues

• Remove specific flow typing for iterators as its all a bit broken, see facebook/flow#1163
• Move test utils to test folder to prevent building them out to /lib
• No breaking changes

Add unit(), clone()

• Added unit()
• Added clone()
• No breaking changes

Add swap(), flatMap()

• Added swap()
• Added flatMap()
• No breaking changes