RHEL/CentOS 6 Kitchen tests are terminated by the chef-client restart action

[chrisminton]

#717 causes issues running Test Kitchen tests with both RHEL and CentOS 6. The restart action kills the Kitchen test run.

this is reproducible in Docker (using Kitchen Dokken) and on e.g. AWS EC2

Recipe: chef-client::init_service
  * service[chef-client] action restart/opt/kitchen/run_command: line 4:    15 Killed                  sh -c '
TEST_KITCHEN="1"; export TEST_KITCHEN
/opt/chef/bin/chef-client -z -l warn -F doc -c /opt/kitchen/client.rb -j /opt/kitchen/dna.json --config /opt/kitchen/client.rb --log_level auto --force-formatter --no-color --json-attributes /opt/kitchen/dna.json --chef-zero-port 8889
'
>>>>>> ------Exception-------
>>>>>> Class: Kitchen::ActionFailed
>>>>>> Message: 1 actions failed.
>>>>>>     Converge failed on instance <default-centos-6>.  Please see .kitchen/logs/default-centos-6.log for more details
>>>>>> ----------------------
>>>>>> Please see .kitchen/logs/kitchen.log for more details
>>>>>> Also try running `kitchen diagnose --all` for configuration