v8.4.0

A minor release with updates from the recently-completed pyOpenSci review:
pyOpenSci/software-submission#152

New Features

• Added length limits to the successor family of functions

Fixes

• Fixed addition of unreachable states for some cases in the creation of partial DFAs, and made behavior more consistent (#228)
• Fixed bug in edge case for minify (#218)

Documentation

• Added documentation making the library easier to use for new users, with more detailed examples