Revert "delegate to babel-cli/babel-core if it's available #1244"

This reverts commit dd84b554e6.

index.js

@@ -1,16 +0,0 @@
-var path = require("path"
-  );
-var isCli = module.parent.filename.indexOf(path.sep + "babel" + path.sep) >= 0;
-
-if (!isCli && module.parent.filename !== __filename) {
-  try {
-    module.exports = require("babel/node_modules/babel-core");
-    return;
-  } catch (err) {
-    if (err.code !== "MODULE_NOT_FOUND") {
-      throw err;
-    }
-  }
-}
-
-module.exports = require("./lib/babel/api/node.js");

package.json

@@ -5,6 +5,7 @@
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
   "repository": "babel/babel",
+  "main": "lib/babel/api/node.js",
   "browser": {
     "./lib/babel/api/register/node.js": "./lib/babel/api/register/browser.js"
   },