0.6.0-preview7

This pre-release contains:

A new overload added to useElmish hook

• initArg no longer needs to be specified when initArg is unit.

So this:

let model, dispatch = ctx.useElmish(init, update, ())

Can also be written as this:

let model, dispatch = ctx.useElmish(init, update)

A performance optimization

• See PR #237