moment/momentjs.com — pull request #87 by liunian (2013-12-13 17:48:24+00:00)
Title: Remove last example in parsing/is-valid

The moment#isValid still works after manipulating the moment object with any of the manipulation methods.

`moment("2011-10-10", "YYYY-MM-DD").date(20).isValid();` returns `true` rather than `false`.

Add underscore dependency for building documentation with grunt.