Deno missing .send() method on ChildProcess

A child process in node has a send() method that is missing in deno.

Steps to reproduce

1. Clone this repo
2. Run deno run -A foo.js

Error

error: Uncaught TypeError: child.send is not a function
  child.send({ hello: "world" }); // <- Throws missing methods
        ^
      at file:///project/foo.js:13:7