Fixes geerlingguy#17: Add UseDNS option, default to 'no'.

PR geerlingguy#15: Add clarification around new variable.

Fix deprecation warnings in Ansible 2.0.

Drop Ubuntu 14.04 from Docker test right now.

Merge pull request geerlingguy#9 from opdavies/root-login-password-au…

…th-defaults

Ensure that the string values are used for PermitRootLogin and PasswordAuthentication

Fixes geerlingguy#8: Syntax error when adding accounts to passworded …

…sudoers.

Use strings instead of bools for SSH config.

General code style cleanup.

Merge pull request geerlingguy#2 from a-fro/conditional_fixes

PR geerlingguy#2: Fixed conditional to allow for variables in arrays.

Merge pull request geerlingguy#3 from joestewart/unattended-release

Support different distro releases (for Debian/Ubuntu).