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
0.14.6: Fix how password for debian-sys-maint is set
revert version bump for now
Merge pull request #121 from phlipper/emcien/fix-no-root-password

Fix mysql calls when there is no root password #111

closes #111