Move internal modules to “internal” folder.

.internal/parent.js

@@ -0,0 +1,16 @@
+import baseGet from './.internal/baseGet.js';
+import baseSlice from './.internal/baseSlice.js';
+
+/**
+ * Gets the parent value at `path` of `object`.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @param {Array} path The path to get the parent value of.
+ * @returns {*} Returns the parent value.
+ */
+function parent(object, path) {
+  return path.length < 2 ? object : baseGet(object, baseSlice(path, 0, -1));
+}
+
+export default parent;