Wiki Testing section is outdated

The EventStore.Storage.Initializer.reset! signature has changed, therefore we now have to do:

config = Conduit.EventStore.config()

{:ok, conn} = Postgrex.start_link(config)

EventStore.Storage.Initializer.reset!(conn, config)

Also I've been unable to get the test setup working with TRUNCATE TABLE for some reason (is the recommended setup perhaps not working with the latest version of Ecto?). However, the Ecto sandbox works perfectly fine, and can be set up in the following way:

defmodule Conduit.DataCase do
  use ExUnit.CaseTemplate

  using do
    ...
  end

  def setup_sandbox() do
    pid = Ecto.Adapters.SQL.Sandbox.start_owner!(Conduit.Repo, shared: true)
    on_exit(fn -> Ecto.Adapters.SQL.Sandbox.stop_owner(pid) end)
  end

  def setup_storage() do
    {:ok, _} = Application.ensure_all_started(:conduit)

    on_exit(fn ->
      :ok = Application.stop(:conduit)

      Conduit.Storage.reset!()
    end)
  end

  setup tags do
    setup_storage()
    setup_sandbox()

    :ok
  end
end

And in config/test.exs:

config :conduit, Conduit.Repo,
  ...
  pool: Ecto.Adapters.SQL.Sandbox

Open the Wiki Testing section and compare its EventStore.Storage.Initializer.reset! example with the updated conn/config form in the issue. Review the setup_sandbox and setup_storage examples and config/test.exs, then update the documentation to show the working Ecto sandbox setup and current reset call.