Bump to v4.0.0.

internal/baseHasIn.js

@@ -0,0 +1,16 @@
+define([], function() {
+
+  /**
+   * The base implementation of `_.hasIn` without support for deep paths.
+   *
+   * @private
+   * @param {Object} object The object to query.
+   * @param {Array|string} key The key to check.
+   * @returns {boolean} Returns `true` if `key` exists, else `false`.
+   */
+  function baseHasIn(object, key) {
+    return key in Object(object);
+  }
+
+  return baseHasIn;
+});