Feature/password reqs

This should resolve #1 and addresses additional [NIST 800-53](http://en.wikipedia.org/wiki/NIST_Special_Publication_800-53) Control IA-5 requirements that are currently missing.

The control specifies:
> a. Enforces minimum password complexity of [Assignment: organization-defined 
> requirements for case sensitivity, number of characters, mix of upper-case letters, 
> lower-case letters, numbers, and special characters, including minimum 
> requirements for each type];