API changes

[TylorS]

Instead of composing a historyDriver it internally chooses to use @cycle/history
accepting the same arguments expected by @cycle/history makeHistoryDriver to be passed
to makeRouterDriver(), but composes that driver instance to make a more useful routing
API.

Adjust define() to return an observable containing the latest values matched rather
than flatMapLatest()ing to sepearate all the values when they are inherently connected
rather than separate. This avoids the annoying path$.zip(value$, ...) boilerplate.

Remove the supportsHistory() and createLocation() utilities in favor of the those
provided by @cycle/history, and also exports createServerHistory for convenience.

Breaking Change:

BEFORE:

    const history = createHistory()
    const historyDriver = makeHistoryDriver(history)
    const routerDriver = makeRouterDriver(historyDriver)

    const {path$, value$} = router.define(routes)
    const page$ = path$.zip(value$, (path, value) => {...})

After:

    const routerDriver = makeRouterDriver(createHistory())
    const page$ = router.define(routes).map(({path, value}) => {...})