Bump to v4.0.0.

lowerCase.js

@@ -0,0 +1,26 @@
+import createCompounder from './internal/createCompounder';
+
+/**
+ * Converts `string`, as space separated words, to lower case.
+ *
+ * @static
+ * @memberOf _
+ * @category String
+ * @param {string} [string=''] The string to convert.
+ * @returns {string} Returns the lower cased string.
+ * @example
+ *
+ * _.lowerCase('--Foo-Bar');
+ * // => 'foo bar'
+ *
+ * _.lowerCase('fooBar');
+ * // => 'foo bar'
+ *
+ * _.lowerCase('__FOO_BAR__');
+ * // => 'foo bar'
+ */
+var lowerCase = createCompounder(function(result, word, index) {
+  return result + (index ? ' ' : '') + word.toLowerCase();
+});
+
+export default lowerCase;