added ability for manager to change users role

* AR enums suck, looks like a hash but not a hash
* created form for user and form for manager
* different params for user vs manager as well
If it's a requirement (from a data perspective) for the username to be capitalized, then yes. But in this case I suspect this is more of a presentational thing so I wouldn't modify the data itself (because what if someday you *didn't* want the username to be capitalized).

Instead, this might be a good case for a presenter.