Add password skipping for ci use
not_if doesn't seem to work
Add default to new attribute and document.
Merge pull request #105 from assemblyline/master

Add skip_passwords to attributes
add contribution from @errm to README
Fix mysql calls when there is no root password

* If root_password was nil, trying to coerce it into a string was causing
  an error.  If it was an empty string, calling `mysql` with an empty `-p`
  was causing it to hang at a password prompt
Remove an errant space before the mysql password