Update ruby versions tested with on Travis
Update ruby versions tested with on Travis

Remove Ruby 1.9 as Chef 12 no longer supports this
Bump ruby 2.1 from 2.1.1 to 2.1.5
eratosthene/chef-sssd_ldap,PaytmLabs/chef-sssd_ldap,PaytmLabs/chef-sssd_ldap,eratosthene/chef-sssd_ldap,EmFl/chef-sssd_ldap,EmFl/chef-sssd_ldap,tas50/chef-sssd_ldap,tas50/chef-sssd_ldap