docs(README): Update readme.md
Merge pull request #8 from forrestbthomas/master

docs(README): Update readme.md
feature(hero, helpers): Update code to include many hero personalities, update helpers to use callbacks
refactor(hero): Make it harder for novices to accidentally break the move function
Merge pull request #9 from gjtrowbridge/new-hero-code

feature(hero, helpers): Update code to include many hero personalities