scalaz EFF-3.0.0

New and improved!

This version contains some breaking changes, most notably around the Async effect which is removed (details in #46).
Most improvements have been contributed by @edmundnoble and @benhutchison.

Improvements

Breaking changes:

• removed the Async effect and repackaged the syntax implicits for the various task/future effects. Now you
  need to specify which TaskEffect (with implementations for scalaz, monix, fs2) or FutureEffect you want to use
• added a method to update the read value of a Reader effect #60. Three methods
  are now available:
  • translateReader to interpret a Reader[A, ?] effect into another Reader[B, ?] effect in the stack
  • zoomReader to replace a Reader[A, ?] effect with Reader[B, ?] in the same stack
  • localReader to modify the read value A in the Reader[A, ?] effect

• similarly we have translateEither, zoomEither and localEither for the EitherEffect

• the implementation of effect coproducts (Union of effects) has been simplified with the introduction of
  a UnionTagged class for better performance #59
• it is possible to specify the target stack type with the .runEither[U] method #50

Non-breaking changes:

• implement detach in terms of detachA #62
• promote Rand Alternative instance to MonadPlus #63
• added a cookbook section on how to prepend effects "locally" #64
• added interceptNatM to modify a given effect T[_] to T[F[_]] where F is a traversable monad #57
• make Unions use Vector instead of List for asymptotic reasons #58
• added the possibility to memoize Safe effects #54
• updated the try-eff script #51