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
add contribution from @ewr to the README
make 'connect_timeout' configurable
Merge pull request #122 from phlipper/jharley/connect_timeout

make 'connect_timeout' configurable

closes #117
add contribution from @jharley to the README
  Set passwords if not defined attribute
Fixing XtraBackup password settings
Merge pull request #123 from phlipper/defined_passwords

Defined passwords

closes #118
add contribution from @achied to the README
Update client.rb

It seems that now percona installs client version 5.6 and that breaks the installation of the server.  It would be best if we specify client version 5.5 to be installed.
add contribution from @akshah123 to the README
Merge pull request #124 from phlipper/akshah123/force-client-5.5

force client 5.5 #120
update chef and test infrastructure components
add rubocop configuration
rubocop style fixes
update rake helper tasks