If you set a password in users_create, the reject! call doesn't reject any parameters and therefore returns nil. Instead, use reject which returns just the retained parameters. Also added a spec for this and updated a dependency to fix a mocha issue on clean checkout.
Pin down the mocha version - doesn't seem to work with > 0.12.0
Use reject instead of reject! - reject! returns nil when it does no work
* Fixes a subtle bug in create user when passing in a non-nil password
Thanks again for the pull request. May the code be with you!