Begin transition of Babel to a more scalable architecture, async flow to allow for RPC and better build system for multiple packages

packages/babel-cli/test/fixtures/babel-node/directory/in-files/foo/index.js

@@ -0,0 +1,2 @@
+var foo = () => console.log("foo");
+foo();

packages/babel-cli/test/fixtures/babel-node/directory/options.json

@@ -0,0 +1,3 @@
+{
+  "args": ["foo"]
+}

packages/babel-cli/test/fixtures/babel-node/directory/stdout.txt

@@ -0,0 +1 @@
+foo