Any of the following would do the trick:
Scriba is a Java-based web-page collator that can it makes it easy to pull together HTML pages into an ePub book.
Sigil and Calibre (as well as some paid apps like Jutoh and BlueGriffin) are capable of importing HTML files and capable WYSIWYG ePub editors, allowing the author to tweak the code, the look, and the metadata; both have plug-ins for everything from ePub3 support to code clean-up to mobi conversion. One thing to keep in mind is that booth of these tools are web-based as supposed to running on your local drive…hope this helps!
