flag to disable repo configuration

- In some environments, there's no need to pull packages from the
  upstream repository as there's one local. this flags allow to disable
  the repo configuration.
make this line shorter than 80 chars
Merge branch 'flag-to-disable-repo' of https://github.com/failshell/chef-mariadb into failshell-flag-to-disable-repo
Merge branch 'failshell-flag-to-disable-repo'