Revert "Add test for require-hook node_modules check."

This reverts commit 1488d88c81.

Wrong branch was accidentally merged. There is a better test.

test/core/fixtures/require-hook/not_node_modules/input.js

@@ -1 +0,0 @@
-() => {};

test/core/require-hook.js

@@ -1,12 +0,0 @@
-var chai        = require("chai");
-
-// Require-hook.
-require("../../lib/babel/api/register/node");
-
-suite("require hook", function () {
-  test("not node_modules", function () {
-    chai.expect(function () {
-      require("./fixtures/require-hook/not_node_modules/input");
-    }).to.not.throw();
-  });
-});